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Solve the following system of equations.

{y=x−5
−x−3y=7
Write your answer as an ordered pair in the form (x,y).

1 Answer

1 vote

Answer:

(2,-3)

Explanation:

I am not sure if you meant the first equation to be y or -y. I solved it as y.

y = x-5 -x -3y =7

I am going to take the second equation and write it as x =

-x - 3y = 7 Give equation

-x = 3y +7 Add 3y to both sides

x = -3y-7 Multiplied each term in the equation by -1 so that x could be positive

I am going to substitute -3y-7 for x in the first equation up above

y = x - 5

y = -3y -7 - 5 Substitute -3y-7 for x

y = -3y -12 Combined -7-5

4y = -12 Added 3y to both sides

y = -3 Divided both sides by 4.

I now know that y is -3, I will plug that into x = -3y-7 to solve for x

x = -3(-3) -7

x = 9-7 A negative times a negative is a positive

x = 2

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