Question

what method of factoring should first be used?
$x^4 - 15x^3 + 56x^2$
answer
greatest common factor
difference of perfect squares
trinomial factoring
none of the above

Explanation:

Step1: Identify common terms

Each term has $x^2$: $x^4 = x^2 \cdot x^2$, $-15x^3 = x^2 \cdot (-15x)$, $56x^2 = x^2 \cdot 56$

Step2: Verify other methods don't apply

Not a difference of squares; trinomial factoring comes after GCF.

Answer:

Greatest Common Factor