x^2-10x+?=(?-?)^2

1 Answer
Oct 13, 2017

x^2-10x+25=(x-5)^2

Explanation:

We want to add a number on the left so we get a perfect square on the right. A quick way to do this is to add (b/2)^2, in this case that is:

(-10/2)^2=25

So:

x^2-10x+25=(?-?)^2

Factoring we get:

x^2-10x+25=(x-5)^2