Question

Please help, need answer fast!

What is the value of m^2 - 2mn + n^2 for m = -2 and n = 4?

a. -36
b. -4
c. 4
d. 36

Answer 1

Instead of plugging in
`m=-2` and
`n=4` right away, notice that

`m^2-2mn+n^2=(m-n)^2`

and now evaluating this expression at the two given values is easier, if only a little:

`((-2)-4)^2=(-6)^2=(-1)^2*6^2=1*36=36`