What is the side length of a square with an area of 25x^2 -30+9 ? I'm completely confused on this problem. I do not understand how to factor using the GCF.

2 answers

There is no GCF here.

I assume your -30 is supposed to be -30x. Right?

(5x-3)(5x-3)

This is a perfect square.
You can tell because 5x times 5x
equals the first term and -3 times -3 equals the 9.

When you have perfect squares in the first and last term of the trinomal try the form (ax -b)(ax-b)

I knew to use negatives because the middle term was a negative.

This can also be written as (ax-b)^2
s^2 = (5x - 3)(5x - 3) = (5x-3)^2
so
s = 5x-3

when in danger or in doubt:
http://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php