−3x−9y=−12
−3x+7y=4
solve for x

Answers

Answer 1

Answer:

[tex] \huge{ \boxed{ \boxed{ \sf{ \red{ \sf{x = 1}}}}}}[/tex]

Step - by - step explanation :

[tex] \underline{ \underline{ \sf{Solution}}} : [/tex]

USING ELIMINATION METHOD :

[tex] \sf{ - 3x - 9y = - 12}[/tex] ••••••• equation ( i )

[tex] \sf{ - 3x + 7y = 4}[/tex] ••••••• equation ( ii )

Subtracting equation ( ii ) from ( i )

Note that while subtracting equation ( ii ) from ( i ) , sign of each term of equation ( ii ) changes and hence becomes 3x - 7y = -4.

[tex] \sf{ \cancel{ - 3x} - 9y = - 12}[/tex]

[tex] \sf{ \cancel{3x} - 7y = - 4}[/tex]

_____________________

➺ [tex] \sf{ - 16y = - 16}[/tex]

➺ [tex] \sf{ \frac{ - 16y}{ - 16} = \frac{ - 16}{ - 16}} [/tex]

➺ [tex] \sf{y = 1}[/tex]

The value of y is 1. Since , we are asked to find the value of x , substituting the value of y in equation ( i) , we get :

➺ [tex] \sf{ - 3x - 9 \times 1 = - 12}[/tex]

➺ [tex] \sf{ - 3x - 9 = - 12}[/tex]

➺ [tex] \sf{ - 3x = - 12 + 9}[/tex]

➺ [tex] \sf{ - 3x = - 3}[/tex]

➺ [tex] \sf{ \frac{ - 3x}{ - 3} = \frac{ - 3}{ - 3}} [/tex]

➺ [tex] \sf{ x = \boxed{ \bold{ \red{ \sf{1}}}}}[/tex]

Hence , the value of x is 1 .

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☞ [tex] \underline{ \sf{Extra \: Info}} : [/tex]

There are many methods to solve such simultaneous equations. They are :

Graphical method : In this method , we find a few pairs of solutions to each of two given equations. The pairs of solutions of each equation are plotted in a graph and by joining them, two separate straight line lines are obtained. The coordinates of the point of intersection of two straight lines are the solutions to the given equation.

Elimination method : In this method, we add or subtract the given equations to eliminate one of the two variable by making their coefficients equal. Then , a single equation with one variable so obtained is solved to find the value of the variable. The value of the variable is substituted to any one equation to find the value of the eliminated variable.

Substitution method : In this method , a variable is expressed in terms of another variable from one equation and it is substituted in the remaining equations.

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✑ Learn more :

Solve system of equations using elimination method :

https://brainly.com/question/20160304

What is the substitution method ?

https://brainly.com/question/15936865

Hope I helped ! ツ

Have a wonderful day / night ♡

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Related Questions

a half of 48 divided by6multiplied by4 plus 3 minus 2

Answers

Answer:

17

Step-by-step explanation:

follow the order of operations (PEMDAS):   half of 48 is 24

24 / 6 = 4

4 x 4 = 16

16 + 3 = 19

19 - 2 = 17

Answer:

17

Step-by-step explanation:

half of 48 is 24

24 divided by 6 is 4

4× 4= 16

16+3= 19

19-2=17

A pulley rotates through 107° in one minute. How many rotations does the pulley make in an hour!
The pulley makes rotations per hour.
(Simplify your answer. Round to the nearest whole number.)

Answers

Answer:

18 rotations.

Step-by-step explanation:

As there are 360 degrees in a circle, by proportion, the time for 1 rotation

= (360/107) * 1

= 3.364 minutes.

So the number of rotations in 1 hour (60 minutes)

=  60 / 3.364

= 17.83

Number of rotations does the pulley make in an hour is 18.

Here,

A pulley rotates through 107° in one minute.

What is rotations?

The action or process of rotating on or as if on an axis or center.

Now,

As there are 360° in a circle, by proportion;

Time for one rotation = (360/107) x 1

                                = 3.364 minutes

Hence, number of rotations in 1 hour

= 60 / 3.364

= 17.83

So, Number of rotations does the pulley make in an hour is 18.

Learn more about the Rotations visit:

https://brainly.in/question/39626227

#SPJ2

On a field trip they take busses and vans. Each bus holds 60 people and each van holds 10 people. If 390 people went on the trip and they took a total of 9 vehicles, how many of each type of vehicle did they take?

Answers

Answer:

6 buses and 3 vans

Step-by-step explanation:

How much of the circle is shaded? Write your answer as a fraction in simplest form.
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Answers

Answer: 19/28

Step-by-step explanation:

3/7 + 1/4

Find the LCM for 7 and 4

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Can some people of brainly do this stuff for my little cousin i dont know what i'm doing.

Answers

Answer:

21=1 x 21

21=3 x 7

Step-by-step explanation:

pls mark brainliest to help rank :)

1) 1

2) 7

i hope you understand

6. Write the equation for the two functions and
compare the rates of change.
Function C
Function D
y
The Used Book
Store will pay $0.50
for each box of
hardcover books.
--2
4
0
2
4

Answers

Answer:

the photo is blank for me

Step-by-step explanation:

Answer with explanation please. Thank youuu​

Answers

Step-by-step explanation:

67-35= 32...do it along the number line dude

Rewrite the fraction in the sentence below as a percentage. In 2002, a popular company made 11/20 of its money online.​

Answers

Answer:

55%

Step-by-step explanation:

11/20 = 0.55

0.55 = 55%

MARKING BRAINLIEST ❤️
(PLZ HELP ACTUALLY...)

An electrician charges $15.00 per hour for an electrical job that requires more
than 4 hours to complete. For any job requiring 4 hours or less, there is a flat
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an expression that gives the charge, in dollars, for a job requiring more than 3
hours to complete.

Answers

$50.75 + ($15.00)x
Plz mark brainliest :)
50.75 + 654 then you will have your answer

why is it not showing the graph

Answers

Answer:

I think you need to upload an image of the graph you can screenshot it

Step-by-step explanation:

how do I find the slope of a line from a table graph ​

Answers

Step-by-step explanation:

slope is the rise over run

rise= X

run= Y

X/Y = slope

1) For a period of time, an island's population grows at a rate of 3.8% per year. If the current
population is 1543, what will the population be in 5.2 years?

Answers

Okay so 3.8% of 1,543 is 58.634 so then you would multiply it by 5.2 for years witch would be 304.8978 so add that to the original witch is 1543 so your answer would be 1847.8978 rounded up would be 1848

Look at pictureeeee look at picture

Answers

Answer:

The answer in decimal form is 18.9 so if you convert it to a fraction, the correct answer should be 8 9/10.

if the gas station has 80 customers on Tuesday, how many customers can be predicted to get a Dr.pepper?

Answers

Answer:

12

Step-by-step explanation:

A catapult’s lever holds a cannonball. The lever is attached to a tightly held rope. When the rope is released, the lever springs forward and launches the cannonball. When the rope is held tightly, which form of energy does it possess?​

Answers

Answer:

elastic

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

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Answers

Answer:

T = 50 + 30w

Step-by-step explanation:

Hope this helps :)

Answer:

T = 40 + 20w

Step-by-step explanation:

The initial amount is 50 and the rate per week is 30.

please help me find the longest side in triangle ABC

Answers

Answer:

The longest side is B

Step-by-step explanation:

(A) 3x+28= 31x

(B) 5x+52=57x

(C) 2x-10= 8x

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The diagram shows the governing system of a municipal government.



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The city council is elected and the mayor is not.
The mayor is elected and the city council is not.
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The city council shares equal power with the mayor.

Answers

Answer:

where is the diagram

Step-by-step explanation:

?

Answer:

C !!!   THE MAYOR HAS MORE POWER THAN THE CITY COUNCIL !!!

Step-by-step explanation:

Gym A charges a $70 sign-up fee and an additional $20 per month. Gym B only charges a $10 sign-up fee, but charges
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Answers

Answer:

What ismthe question lol

At one farmer’s market, bananas cost $0.80 per pound. At another farmer’s market, bananas are sold in 5-pound bags for $4.50 per bag. Which explains how to find the better buy?
Divide 4.50 by 5 to find the unit rate for the 5-pound bag, and compare that number to $0.80 per pound.
Divide 0.80 by 5 to find the unit rate for the 5-pound bag, and compare that number to $0.80 per pound.
Multiply 4.50 by 5 to find the cost for 5 pounds, and compare to $4.50 per bag.
Multiply 4.50 by 0.80 to find the cost for 5 pounds, and compare to $4.50 per bag.

Answers

Answer:

It's the first one

Step-by-step explanation:

To find the price per pound, you have to divide 4.50 by 5, which you then compare to $0.80

Answer:

its a in edg

Step-by-step explanation:

just took the test peace out home fry

PLEASE ANSWER< WILL GIVE BRAINLY TO BEST ANSWER!?

Answers

Answer: D is the correct answer.

Step-by-step explanation: The triangle inequality theorem states that the sum of any two sides of a triangle must be greater than the third side and answer D does exactly that because 2.6 + 8.1 =10.7 which is greater than the third side which would be 10.2.

PLEASE HELP! it’s would be really appreciated

Answers

Answer:

46 degrees

Step-by-step explanation:

180 - 102 - 32 equals to 46

Tell which number is greater.

37/50, 37%

Answers

Answer:

37/50

Step-by-step explanation:

because 37% is out of 100

Answer:

37/50

Step-by-step explanation:

as 37% means 37/100, when 37 is divided by a smaller number such as 50, the result will be greater.

Sorry, but can someone PLEASE help me Change 2 3/16 to an exact decimal. I'll give you 15 points

Answers

2.1875

If you divide your numerator and denominator you’ll get 0.1875. Add the integer to it and you’ll get 2.1875. So, 2 3/16 = 2.1875.

I hope this helps!

Answer:

2.1875

Step-by-step explanation:

2 3/16 to decimal form is 2.1875.

I NEED HELPPPPPPPPPPPPPPP

Answers

It should be either A or B but I can’t figure it out from there, it at least slims down your choices


Perform the calculation then
round to the appropriate number
of significant digits.
5207 - 24.2
Hint: Look at the number that has the FEWEST sig figs to
determine how many sig figs should be in your answer.
(24.2 has 3 significant digits, so your answer should have
3 significant digits.)
Enter

Answers

Answer:

it is 69.5

Step-by-step explanation:

Find the missing angles.
10°
55°
LO
x=
y =
Z=
o
X=
0
y=
o
Z=

Answers

Step-by-step explanation:

x = 90- 55 = 35

y = 180- x

y= 180 - 35 = 145

z =180- (y +10)

z = 180 - (145 +10)

z = 180-155

z = 25

Please gimme brainliest

A bookstore charges a standard rate for paperback or hardback books. The cost of a paperback book is 4 dollars less than the cost of a hardback book.​ Recently, one day of sales totaled ​$1065.10. That day the bookstore sold 51 paperback books and 47 hardback books. Write a system representing this situation. Use the graph to estimate the solution of the system. What does the solution mean in this​ situation? How much does each type of book​ cost? Use substitution to verify your solution.

Answers

Answer: for one hard cover book it is about $17 and paperback is $13

Step-by-step explanation:

18x -1 (-3x + 9) distributing a negative number (plz I need help I need to get this done ASAP)

Answers

Answer:

18−1(−3x+9) 18+3−9

Step-by-step explanation:

Answer:

-54x+156

I dunno if it's correct

Plz help answer these questions

Answers

Answer:

Step-by-step explanation:

If you download Socratic it give u all the answers for free

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