Respuesta :

devishri1977

Answer:

Step-by-step explanation:

x² + 4x -21 = x² + 7x - 3x -3*7

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

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

AnthonyFleming

Answer:

(x+7)(x-3)

Step-by-step explanation:

You can factor this trinomial into two binomials. 7 * -3 multiply together to form -21 and they add together to form 4.