Question

Trinomial help?
(a + b - c)(a + b + c)
My answer: a^2 + 2ab + ac + b^2 + bc
I don't think that's exactly right. Can you help?

Answer 1

This looks good, except the last part is not bc, but instead -c^2

Answer 2

And ac is not supposed to be there.

Answer 3

It should look something line a^2+2ab+b^2-c^2

Answer 4

Notice that in your equation, it has -c, so you must subtract.

Answer 5

Thanks, that was exactly what I needed @zordoloom :)

Answer 6

Sure thing!