Question

Question #0cec2

Answer 1

`15" and "3`

Explanation:

`"let the 2 numbers be "x" and "ycolor(white)(x);x>y`

`"then "x+y=18to(1)`

`"and "x-y=12to(2)`

`"adding the equations together will eliminate y"`

`"adding term by term on both sides"`

`(x+x)+(y-y)=(18+12)`

`rArr2x=30`

`"divide both sides by 2"`

`(cancel(2) x)/cancel(2)=30/2`

`rArrx=15`

`"substitute this value into equation "(1)`

`rArr15+y=18rArry=18-15=3`

`"the numbers are "15" and "3`

`15+3=18" and "15-3=12`

Answer 2

`x=15`
`y=3`

Explanation:

Alright, lets think of this problem as two different equations: `x+y=18` and `x-y=12`. Your trying to solve for `x` and `y`.

We need to get rid of one of those variables. Since there is a positive and a negative `y`, all we have to do is add both equations!

`x+y=18`
`x-y=12`

`2x=30`

`x=15`

Now we just plug this `x` value into one of the original equations to get `y`.

`15+y=18`
`y=3`

Now to check, we are going to plug the `x` and `y` into `x-y=12` to make sure out answer is correct.

`15-3=12`

`12=12`

Hope this helped!
~Chandler Dowd