Question

Teresa is factoring this polynomial by grouping. Which common factors should be used in the next step of factoring?

10x3+3x2−20x−6

(10x3+3x2)+(−20x−6)

x2 and −2x
2x2 and −2x
x2 and −2
2x2 and −2

Answer 1

x^2 and −2

Because 10x^3+3x^2 = x^2(10x+3) and −20x−6 = −2(10x+3), giving (10x+3)(x^2−2).