Question

Factoring polynomials 3x^2+42x+72

Answer 1

Answer:

3(x + 12)(x + 2)

Step-by-step explanation:

Given

3x² + 42x + 72 ← factor out 3 from each term

= 3(x² + 14x + 24) ← factor the quadratic

Consider the factors of the constant term (+ 24) which sum to give the coefficient of the x- term.

The factors are + 12 and + 2, since

12 × 2 = 24 and 12 + 2 = 14, thus

x² + 14x + 24 = (x + 12)(x + 2) and

3x² + 42x + 72

= 3(x + 12)(x + 2) ← in factored form