Is $(-2-2)^2 - (-2+3)(-2-3)-4(-2^2+2) = 69$?

Question

I get 69 when I calculate this, but my calculator says it's 29. I've gone over this several times and can't figure out why I'm wrong. I'm also not entirely sure if I've used the calculator properly.

What answer is correct, and any idea where I'm heading wrong here?

Answer 1

You have used you calculator properly. It is

$$(-2-2)^2=(-4)^2=16,$$ $$(-2+3)(-2-3)=1\cdot (-5)=-5,$$ and $$-4(-2^2+2)=-4(-4+2)=-4(-2)=8.$$ Thus, you get

$$16-(-5)+8=16+5+8=29.$$

Answer 2

I believe your calculator is correct.

\begin{align*} &(-2-2)^2-(-2+3)(-2-3)-4(-2^2+2)\\ &=(-4)^2-(1)(-5)-4(-4+2)\\ &=(16)-(-5)+16-8\\ &=16+5+16-8\\ &=21+8\\ &=29 \end{align*} Note that $-2^2=-4$ whereas $(-2)^2=4$.