Answer:
The solution to a system of linear equations is the ordered pair (or pairs) that satisfies all equations in the system. The solution is the ordered pair(s) common to all lines in the system when the lines are graphed.
Lines that cross at a point (or points) are defined as a consistent system of equations. The place(s) where they cross are the solution(s) to the system.
Parallel lines do not cross. They have the same slope and different y-intercepts. They are an example of an inconsistent system of equations. An inconsistent system of equations has no solution.
Two equations that actually are the same line have an infinite number of solutions. This is an example of a dependent system of equations.
Step-by-step explanation:
Solve the system of equations graphically.
3x + 2y = 4
−x + 3y = −5
Solution
Graph each line and determine where they cross.
The lines intersect once at (2, −1).
A graphic solution to a system of equations is only as accurate as the scale of the paper or precision of the lines. At times the point of intersection will need to be estimated on the graph. When an exact solution is necessary, the system should be solved algebraically, either by substitution or by elimination.
Substitution Method
To solve a system of equations by substitution, solve one of the equations for a variable, for example x. Then replace that variable in the other equation with the terms you deemed equal and solve for the other variable, y. The solution to the system of equations is always an ordered pair.
Example
Solve the following system of equations by substitution.
x + 3y = 18
2x + y = 11
Solution
Solve for a variable in either equation. (If possible, choose a variable that does not have a coefficient to avoid working with fractions.)
In this case, it's easiest to rewrite the first equation by solving for x.
x + 3y = 18
x = −3y + 18
Next, substitute (−3y + 18) in for x into the other equation. Solve for y.
2( 3y + 12x + y = 11
2(−3y + 18) + y = 11-------Substitute -3y + 18 in for
−6y + 36 + y = 11-------Distribute.
2(3y −5y + 36 = 11-------Combine like terms.
2(3y + 18−5y = −25-----Subtract 36 from both sides
2(3y + 18) + y = 5---- -Divide both sides by -5.
Then, substitute y = 5 into your rewritten equation to find x.
x = −3y + 18
x = −3(5) + 18
x = −15 + 18
x = 3
Identify the solution. A check using x = 3 and y = 5 in both equations will show that the solution is the ordered pair (3, 5).
Elimination Method
Another way to solve a system of equations is by using the elimination method. The aim of using the elimination method is to have one variable cancel out. The resulting sum will contain a single variable that can then be identified. Once one variable is found, it can be substituted into either of the original equations to find the other variable.
Example
Find the solution to the system of equations by using the elimination method.
x − 2y = 9
3x + 2y = 11
Solution
Add the equations.
x − 2y = 9
3x + 2y = 11
4x + 2y = 20
Isolate the variable in the new equation
4x = 20
x = 5
Substitute x = 5 into either of the original equations to find y.
x − 2y = 9
(5) − 2y = 9
−2y = 4
y = −2
Identify the ordered pair that is the solution. A check in both equations will show that (5, −2) is a solution.
It may be necessary to multiply one or both of the equations in the system by a constant in order to obtain a variable that can be eliminated by addition. For example, consider the system of equations below:
3x + 2y = 6
x − 5y = 8
Both sides of the second equation above could be multiplied by −3. Multiplying the equation by the same number on both sides does not change the value of the equation. It will result in an equation whereby the x values can be eliminated through addition.
Special Cases
In some circumstances, both variables will drop out when adding the equations. If the resulting expression is not true, then the system is inconsistent and has no solution.
4x + 6y = 13
6x + 9y = 17
3(4x + 6y = 13)
2(6x + 9y = 17)
12x + 18y = 39
12x + 18y = 34
0 = 5
The equation is false. The system has no solution.
If both variables drop out and the resulting expression is true, then the system is dependent and has infinite solutions.
6x + 15y = 24
4x + 10y = 16
2(6x + 15y = 24)
3(4x + 10y = 16)
12x + 30y = 48
12x + 30y = 48
0 = 0
The equation is true. The system has an infinite number of solutions. (Notice that both of the original equations reduce to 2x + 5y = 8. All solutions to the system lie on this line.)
Three-fourths of the difference of a number and 7 is negative fifteen. What is the number? (Please solve very clear and step by step and I'll give u brainlest)
Answer:
- 13Step-by-step explanation:
Three-fourths of the difference of a number and 7 is negative fifteen:
3/4*(x - 7) = - 15x - 7 = - 15*4/3x - 7 = - 20x = 7 - 20x = - 13find the perimeter of the triangular shaped sandwich
Answer:
P = 12 + 5x
Step-by-step explanation:
P = a + b + c
P = 7 + (x + 4) + (4x + 1)
= 7 + x + 4 + 4x + 1
= 12 + 5x
Bella conducted a scientific experiment. For a certain time, the temperature of a compound rose
3
1
3
3
3
1
degrees in
15
15 minutes. What was the rate, in degrees per hour, that the temperature of the compound rose?
Answer: 13 1/3 degrees per hour
Explanation: 10/3 x 4 = 40/3
40/3 = 13 1/3
d) A patient is given 11÷2ml of medicine three times a day. How long does a bottle of 132 ml of medicine last?
Answer: 8 days.
Explanation;
11/2 = 5.5
5.5 x 3 = 16.5
132/16.5 = 8
Answer:
8 days
Step-by-step explanation:
So, 11/2 * 3 = (33/2) = 16.5 ml
Let the number of days medicine last be 'x'.
⇒ 16.5 * x = 132
⇒ x = 132/16.5
⇒ x = 8.
Therefore, Medicines last for 8 days.
Hope it helps!
Which of the following is a solution to the given equation?
y=-3x - 7
A)
(-2,-1)
B)
(-1,-10)
C
(4,-5)
D
(3,-2)
Answer: A
Step-by-step explanation:
By replacing in the given equation:
y=-3x-7
y=-3(-2)-7
y=6-7
y=-1
But for choices B, C and D the given x values don't fit with the images.
13. For a weekly car rental, a car-rental company charges customers a flat fee of $100 plus
10 cents for every mile traveled.
15 Write an equation for the amount, A dollars, of a weekly rental for a car that travels
m miles.
16
Create a table of m and A values using the equation from part a for 150, 200, and
250 miles.
Answer:
a) y = 0.10(16) + 100
y = $ 101.60
b) y = 0.10(150) + 100
y = $115
c) y = 0.10(200) + 100
y = $120
d) y = 0.10(250) + 100
y = $125
Step-by-step explanation:
Multiply (3x+2)(x-6)
What is the middle term of the simplified answer?
Answer:
16x
Step-by-step explanation:
(3x + 2) (x - 6)
Multiply 3x by x and -6
3x^2 - 18x
Multiply 2 by x and -6
2x - 12
Combine like terms
3x^2 - 16x - 12
The middle term is 16x
The books have been sorted into fiction and nonfiction. The number of fiction books is 5 less than 4 times the number of nonfiction books. The books are 70% fiction. Choose the equation that best represents this scenario.
x over quantity 4 times x minus 5 end quantity equals 30 over 100
x over quantity 4 times x minus 5 end quantity equals 30 over 70
The number of fiction books are 7 and number of non fiction books are 3 respectively
let
number of fiction books = x
number of non fiction books = y
x = 4y - 5
Total books = z
x = 70% of z
y = 30% of z
x + y = z
4y - 5 + 30%(z) = z
4y - 5 + 0.3z = z
4y - 5 = z - 0.3z
4y - 5 = 0.7x
4y - 5 = 0.7z
4(0.3z) - 5 = 0.7z
1.2z - 5 = 0.7z
-5 = 0.7z - 1.2z
-5 = - 0.5z
z = -5/-0.5
z = 10
Therefore,
the number of non fiction = 30% of z
= 0.3 × 10
= 3
number of fiction = 70% of z
= 0.7 × 10
= 7
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express 7 minutes, 30 seconds as a percentage of 1 hour
Answer:
did u mean 7 minutes & 30 seconds or
do you need seperate percentage for each ???
Answer:
420 i think
Step-by-step explanation:
7 mins
7×60
=420
plus the 30sec
450 sec
450/3600×100
45000/3600
450/36
12.5
Both questions 7 and 8
9514 1404 393
Answer:
7. $10,459.28
8. $30,060.93
Step-by-step explanation:
Your table 12-2 will tell you the present-value multiplier of the annual payment for a 10-year annuity due will be ...
7%: 7.515232
11%: 6.537048
__
7. The 11% table value will be used with a payment of $1600 to find the present value:
6.537048 × $1600 = $10,459.28 . . . present value of the annuity due
__
8. The 7% table value will be used with a payment of $4000 to find the present value:
7.515232 × $4000 = $30,060.93 . . . present value of the annuity due
There are a total of 66 people attending a carnival. The ratio of adults to children is 4 to 7. How many adults are attending the carnival? Enter your answer in the box. adults
Answer:
24 adults
Step-by-step explanation:
The equation to represent the scenario is
4x + 7x = 66
Combine like terms
11x = 66
Isolate x
x = 6
To find the amount of adults attending the carnival, substitute 6 with x.
6*4 = 24 adults
7*4 = 42 children
24 + 42 = 66 people in total
Pls help meeee the question is in the photo pls no links or fake answers pls answer both questions
Answer:
Step-by-step explanation:
First one is TRUE...you'd multiply by negative one third
Second is FALSE...no multiplication needed to get x as a positive.
Help help help please good luck be honest
Answer:
A'(-6,4) B'(2,2) C'(-2,-2)
Step-by-step explanation:
The dilation is by 2. This just means you multiply each number by two. FOr example, for point a, multiply -3 by 2 and 2 by 2 to get (-6, 4).
You read online that a 15 ft by 20 ft brick patio would cost about $2,275 to have professionally
installed. Estimate the cost of having a 24 by 27 ft brick patio installed.
Answer: 4914
Step-by-step explanation:
multiply 15 and 20 to make 300
multiply 24 and 27 to make 648
set up proportion
[tex]\frac{300}{648}[/tex] × [tex]\frac{2275}{x}[/tex]
cross multiply
300x = 648(2275)
300x = 1474200
x = 4914
Let F(x) =( 3x/2) - (14/3) for x = 4. What is the value for F(x)
Answer:
f(4) = 1.4
Step-by-step explanation:
f(x) = (3x/2) - (14/3)
We are given that x = 4
f(4) = (3(4)/2) - (14/3)
f(4) = (12/2) - (14/3)
f(4) = 6 - (14/3)
14/3 as a decimal is 4.6
f(4) = 6 - 4.6
f(4) = 1.4 (approximately)
Complete the table of values for this equation: y = 3x +10 Enter your answer by filling in the boxes. x y 4 5 6
x=4,5,6
x=4
[tex]\\ \sf\longmapsto y=3(4)+10[/tex]
[tex]\\ \sf\longmapsto y=12+10=22[/tex]
x=5
[tex]\\ \sf\longmapsto y=3(5)+10=15+10=25[/tex]
x=6
[tex]\\ \sf\longmapsto y=3(6)+10=18+10=28[/tex]
Step-by-step explanation:
y = 3x + 10
x = 4, 5, 6Soo :
y = 3(4) + 10 = 12 + 10 = 22
y = 3(5) + 10 = 15 + 10 = 25
y = 3(6) + 10 = 18 + 10 = 28
Find a 33 matrix Sij so that the product SijA is the same as the matrix A after applying the row operation Ri $ Rj .
Answer:
We want the ith row of the new matrix SijA to be the old jth row of A, so we need the ith row of Sij to extract the jth entry of column of A.
This mean the ith row of Sij must have a 1 in the jth entry and 0's everywhere else.
Similarly, the jth row of Sij must have a 1 in the ith entry and 0's everywhere else.
in the piecewise notation this is
(Sij)kl ={1 if k=i and l=j, 1 if k=k and l=i; 1 if k=l but k#i,j, 0 otherwise
Step-by-step explanation:
describe how you know this is a proportional relanshoships
Answer:
don't see the relationship, but if it's a proportional relationship it should have the same result every time you divide the x by the y or vice versa.
.
Explain why the two figures below are not similar. Use complete sentences and
provide evidence to support your explanation. (10 points)
Answer:
These figures are not the same because the Slope of DE is not the same as the slope of JK.
Step-by-step explanation:
Slope of DE = -2/1
Slope of JK = -1
If they were similar, the slope would be the same, but the size would not.
-Chetan K
Lindsey drew a scale of a city. the scale of the drawing is 1 inch = 3 yards. If the actual length of a neighborhood park is 114 yards, how long is the park in the drawing?
Answer:
38 in
Step-by-step explanation:
114 yds divided by 3 = 38 in
1
2
3
4
5
6
7
8
9
10
Which graph shows a set of ordered pairs that represent a function?
oly
4
4
3
3
3
.
.2
.
2
.
2
1+
1
-5 -4 -3 -2 -11
1 2 3 4 5
-5-4-3-2-1
213
45
x
-5-4-3-2-11
1
2 3
5
-2
42
3
o
3
4
.
14
.
45
O
5
4
3
2
1
-54-3-2-11
2
4
5
X
3rd graph, far right on top
Step-by-step explanation:
Use the vertical line test to determine (one input for x cannot have two outputs of y)
Are the ratios 2:1 and 11:9 equivalent?
Answer: No
Step-by-step explanation:
2 is double 1.
Because 11 is not double 9, the ratios are not equivalent.
Hope it helps :)
plz help with my math plz!!!!
Step-by-step explanation:
This is an isosceles triangle because in an isosceles triangle angles opposite to each of the equal sides must also be equal. Since the diagram shows 2 equal angles we can say its isosceles.
So 3(x+2) = 24
8= x+2
x = 6
Answer:
x = 6
Step-by-step explanation:
The triangle given is an isosceles triangle.
Which means, the two sides and the two angles will be the same.
One of the sides is 24.
The other is 3 ( x + 2 )
Hence, we will get this equation.
24 = 3 ( x + 2 )
24 = 3x + 6
24 - 6 = 3x
18 = 3x
6 = x
Thus, x = 6.
I hope it helps.
A 13 foot ladder is placed
5 feet away from a wall
How many feet up the wall
will the ladder reach?
Answer: 12 feet up
Step-by-step explanation:
This problem models a right triangle, in which the ladder is the hypotenuse and the distance away from the wall is one of the legs. Thus, you may use the Pythagorean Theorem (a^2 + b^2 = c^2)
[tex]a^2+b^2=c^2\\5^2+b^2=13^2\\25+b^2=169\\b^2=144\\b=12[/tex]
N.B. There are some very useful sets of numbers that can help you with this unit.
They are called Pythagorean triplets, and they are the sets of whole numbers that make right triangles. The important ones are 3, 4, 5, and 5, 12, 13 (And their multiples, like 6, 8, 10(3,4,5 *2))
Hope it helps :) and let me know if you want me to elaborate further.
167.67 divided by 8.1
Answer:
167.67 divided by 8.1 = 20.7
Four times the product of a number x and a number y is equal to 20.
Step-by-step explanation:
4x×y=20
.....
..................................
The expression for four times the product of a number x and a number y is equal to 20 is 4xy = 20.
Given,
Four times the product of a number x and a number y is equal to 20.
We need to write the expression.
What is the meaning of the mathematical terms?- 2 times M = 2 x M
- Product of M and N = M x N
- 3 more than M = M + 3
- 3 less than M = M - 3
Find the expression.
We have,
Four times the product of a number x and a number y is equal to 20.
Here,
The product of a number x and a number y can be written as:
= (x) x y
Four times the product of a number x and a number y can be written as:
= 4 x [ (x) x y ]
- is equal to 20 can be written as:
= 20
Now,
We get,
4xy = 20
Thus the expression for Four times the product of a number x and a number y is equal to 20 is 4xy = 20.
Learn more about how to write an expression here:
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whats the answer can someone answer please
Answer:
both are c
Step-by-step explanation:
The price of gas goes up to $3.24 per gallon after a 9.4% increase. What was the price before the increase?
Answer:
i think this correct
Step-by-step explanation:
3.24=(1+9.4/100) x
then x= 2.961 $
g^x+1 =27 solve for x
Answer:x=-3.5
Step-by-step explanation:
If p=7, then what is the value of 8×p−68×p-6?
A
6
B
9
C
50
D
56
Answer:
d
Step-by-step explanation:
you need to type it in the calculator and solve it