Question

How do you solve the system of equations `x+y = 12` and `-10x+6y=-72`?

Answer 1

`y=3,x=9`

Explanation:

You can really do what method you want but for this time I'm going to use the subtraction method. Apply the following:

`x+y=12`
`-10x+6y=-72`

Now I extend the first term by 10.

`x*10+y*10=12*10= 10x + 10y = 120`.

Now take these terms plus eachother:

`10x+10y=120`
`-10x+6y=-72`

To get:

`16y=48`

Divide 16 on both sides to get

`y=3`

Now put that into:

`y+x=12`

To get:

`3+x=12`

Minus three on both sides to get

`x=9`

Check your work by putting them into the equations to see that they are accurate.

Hope this helps.