Question

Factor the polynomial completely.
12x2 + 11x – 15 = 0

Answer 1

(4x−3)(3x+5)=0

Explanation:

Find two numbers whose product is the leading coefficient times the last term and whose sum is the middle coefficient.

ac=−180 b=11

The numbers are −9 and 20.

Rewrite the middle term.

12x2−9x+20x−15=0

Factor by grouping.

3x(4x−3)+5(4x−3)=0

(4x−3)(3x+5)=0

Answer 2

x = -3/4 = -0.750
x = 5/3 = 1.667

The first term is, 12x2 its coefficient is 12 .
The middle term is, -11x its coefficient is -11 .
The last term, "the constant", is -15