Question

Which are zeros of the following polynomial?

6x 2 - 11x - 10 = 0

A x = 6, x = 10
B x = ; x =
C x = -2; x = 5
D x = ; x =

Answer 1

x = -2/3; x = 5/2.

Explanation:

6x 2 - 11x - 10 = 0

Use the 'ac' method:

6 * -10 = -60. We need 2 numbers whose product is -60 and whose sum is -11.

That would be -15 and +4. So we write:

6x^2 - 15x + 4x - 10 = 0 Factor by grouping:

3x(2x - 5) + 2(2x - 5) = 0

(3x + 2)(2x - 5) = 0

x = -2/3; x = 5/2.