Question

3. Factor 2x2 + 11x + 5

A. (2x + 1)(x + 5)
B. (2x + 5)(x + 1)
C. (2x + 1)(x + 11)
D. (2x + 11)(x + 1)

Answer 1

A. (2x + 1)(x + 5).

Explanation:

Factor 2x^2 + 11x + 5

Use the ac method:

2 * 5 = 10.

We need 2 numbers whose product is + 10 and whose sum is +11.

They are + 10 and +1 so we write:

2x^2 + 10x + x + 5

Factor by grouping:

= 2x(x + 5) + 1(x + 5)

The x + 5 is common so we get:

(2x + 1)(x + 5).