Question

If `x^2-y^2=28` and `x-y=8`, what is the average of `x` and `y`?

Answer 1

Average of x and y is `1 3/4`

Explanation:

`x-y=8 ; x^2-y^2=28 or (x+y)(x-y)=28 or 8(x+y)=28 or x+y= 28/8 or x+y=7/2`.
So `x+y=7/2`
Average of x and y is `(7/2)/2 or 7/4 or 1 3/4` [Ans]