Question

$4x {?}^{2} + 8x - 21$
​

Answer 1

Answer:

(2x+3)(2x-7)

Step-by-step explanation:

4x^2-14x+6x-21

2x(2x-7)+3(2x-7)

=(2x+3)(2x-7)

(2x+3)(2x-7)

Answer 2

$4 {x}^{2} - 8x - 21 \\ \\ = > 4 {x}^{2} - 14x \: + \: 6x \: - 21 \\ \\ = > 2x(2x - 7) \: + \: 3(2x - 7) \\ \\ = > (2x + 3)(2x - 7)$