Verified Answer :

iGreen

Expand (x - 5)^2

(x - 5)^2 = (x - 5)(x - 5)

Multiply all the terms in the first parenthesis to all the terms in the 2nd:

x x = x^2
x
-5 = -5x
-5 x = -5x
-5
-5 = 25

So we have:

x^2 - 5x - 5x + 25

Combine like terms:

x^2 - 10x + 25

Plug it back in:

y = (x - 5)^2 - 2

y = x^2 - 10x + 25 - 2

Combine like terms:

y = x^2 - 10x + 23

\(y=(x-5)^2-2\\ y=x^2-10x+25-2\\ y=x^2-10x+23\)