Question

How do you solve `x + y = 4 and x – y = 6`?

Answer 1

`x=5 and y = -1`

Explanation:

We have,

`x+y=4`

or

`x=4-y" "(1)`

Now, we have

`x-y=6`

or

`(4-y)-y=6" "`[from `(1)`]

or

`4-2y=6`

`-2y=6-4`

`-2y=2`

y= -1#

So

`x+y=4`

or

`x-1=4`

`x=4+1`

`x=5`