Question

How do you solve by elimination `8x + 3y= -9` and `-8x + y = 29`?

Answer 1

• We can Add the two equations to eliminate `x`

`8x + 3y= -9`
`-8x + y = 29`
.________

`(cancel(8x)+(-cancel(8x))) +(3y+y) = -9+29`

`4y = 20`

Dividing both sides by 4, we get :

`(4y)/4 = 20/4`

`y = 5`

Substituting `y = 5` in the second equation, we get:

`-8x + 5 = 29`

Transposing 5 to the other side we get:

`- 8x = 29 - 5`

`-8x = 24`

Dividing both sides by `-8` will give us:

`(-8x)/-8 = 24/-8`

`x = -3`

The Solution to the above equations is:

`color(green)(x = -3 and y = 5`

• Verify your answer

Substitute these values of `x and y` in any of the equations and check if both sides equal each other.