Question

Can someone help me factor this?

$x^{2} -4x+4$

A) $(x+2)^{2}$
B) $(x-2)^{2}$
C) $(x+4)^{2}$
d) $(x-4)^{2}$

Thanks!

Answer 1

(a+b)^2=a^2+2ab+b^2

(a-b)^2=a^2-2ab+b^2

x^2-4x+4=x^2- 2*2*x +2^2=(x-2)^2

The answer is B

You can check like this:

(x-2)^2=(x-2)(x-2)=x*x-2x-2x+4=x^2-4x+4