Respuesta :

( x - 2 ) ( x + 10 ) = 13
x ² + 10 x - 2 x - 20 = 13
x ² + 8 x - 33 = 0   (the quadratic  equation ):[tex] x_{12} = \frac{-8\pm \sqrt{64 + 132} }{2}= \frac{-8\pm14}{2} [/tex]
x 1 = 3,  x 2 = -11
Answer: a ) x = 3  ( one solution )