Question

$x^{2} -4x-21=0$

Answer 1

x^2 -4x -21 = 0

= x=7

x= - 3

Explicación paso a paso:

x^2 -4x -21 = 0

(x-7)(x+3)=0

x-7=0

x+3=0

= x=7

x=-3