Question

Solve the simultaneous equations
3x−4y=18
3x−y=9

Answer 1

`x=2, y=-3`

Explanation:

Multiply the first equation by -1 to have your two equations now be:

`-3x+4y=-18`

`3x-y=9`

Then add the two equations to get:

`3y=-9`

Divide both sides by 3 to reach:

`y=-3`

Then substitute
`y` for
`-3` in either of the two first original equations and solve for x, getting:

`x=2`

Hope this helps :)

Answer 2

-3

Explanation:

Difference on each side is +3y and -9

3y=-9

y=-3