What is the solution of the system? Use elimination. 3x-4y=9, -3x+2y=9

Question

what is the solution?

Answer 1

Elimination method

3x-4y = 9 ---------> (1)

-3x+2y = 9 ----------> (2)

To eliminate the x value add the equations (1) and (2).

  3x-4y = 9

-3x+2y = 9

__________

-2y = 18

Divide to each side by negitive 9.

-2y/-2 = 18/-2

⇒ y = -9

Substitute the y value in (1).

3x-4*-9 = 9

3x+36 = 9

Subtract 36 from each side.

3x+36-36 = 9-36

3x = -27

Divide to each side by 3.

3x/3 = -27/3

⇒ x = -9

Solution is x = -9, y = -9.