Question

Can someone double check this for me?
(x-10)(x+10)
x * x = x^2
x * 10 = 10x
-10 * x = -10x
-10 * 10 = -100
= x^2 + 10x - 10x - 100
= x^2 + x - 100

Answer 1

No.

Answer 2

10x-10x=0

Answer 3

= x^2 + 10x - 10x - 100
=x^2-100
in general, (a+b)(a-b)=a^2-b^2

Answer 4

=> x(x+10) - 10(x + 10)
=> x^2 + 10 - 10x - 100
=> x^2 - 10x - 90
Wrong!

Answer 5

I'm using the FOIL method in this people..

Answer 6

Answer would be the same, whatever method you use.