Question

"Find f(­-4) if f(x) = x^2 - x"
Would the answer be -20?

Answer 1

replace every x with -4

so x^2 turns into (-4)^2. Notice how the negative is inside the parenthesis. We are squaring all of -4

Answer 2

f(x) = x^2 - x

f(-4) = (-4)^2 - (-4)

f(-4) = ???

Answer 3

Oh I see! I totally forgot about the parenthesis. So it'd end up the opposite: 20. Thank you!

Answer 4

20 is correct