How do you factor x^2-4x+4x24x+4 using the perfect squares formula?

1 Answer

x^2-4x+4=(x-2)^2x24x+4=(x2)2

Explanation:

I think what is being referred to is the relationship:

(a+b)^2=a^2+2ab+b^2(a+b)2=a2+2ab+b2

We've been given the equation x^2-4x+4x24x+4 - let's factor using the above relationship.

We can take the x^2x2 term and therefore assign x=ax=a. We can also see that the +4+4 can be assigned to the b^2b2 term, giving b=pm2b=±2.

Lastly, we can take the -4x4x term, assign it to the +2ab+2ab and say:

-4x=2ab4x=2ab

-2x=ab2x=ab

We can substitute xx in for aa:

-2x=xb2x=xb

-2=b2=b

and this tells us we will use b=-2b=2 and not b=2b=2.

All in all, we'll get:

x^2-4x+4=(x-2)^2x24x+4=(x2)2