Question

Solve systems of equations for y and x:

−9x + 4y = 6

9x + 5y = −33
​

Answer 1

`y = -3`

`x = -2`

Explanation:

Given

`-9x + 4y = 6`

`9x + 5y = -33`

Required

Find x and y

To eliminate x, we simply add both equations

`-9x = 9x + 4y + 5y= 6 - 33`

`9y= -27`

Divide by 9

`y = -27/9`

`y = -3`

Substitute -3 for y in
`9x + 5y = -33`

`9x + 5 * -3 =-33`

`9x - 15 =-33`

Add 15 to both sides

`9x =-15 -33`

`9x =-18`

Divide by 9

`x = -18/9`

`x = -2`