Question

Unlimited

Factor by grouping (sometimes called the ac-method).
4x² + 3x - 10
First, choose a form with appropriate signs.
Then, fill in the blanks with numbers to be used for grouping.
Finally, show the factorization.
Form:
o
Ax? +
1 x + x - 10
Х
$
4x
+
x - l * - 10
4x?
[ x + x - 10
4x?
x - 10
Factorization:

Answer 1

(4x - 5)(x + 2).

Explanation:

4x^2 + 3x - 10

4 * 10 = -40

We need 2 numbers whose product is -40 and whose sum is +3.

Theses are = - 5 and + 8.

So we write:

4x^2 + 8x + -5x - 10

= 4x(x + 2) - 5(x + 2)

= (4x - 5)(x + 2).