Respuesta :

KONSETON
(x-9) (x+2)=x²+2x-9x-18=x²-7x-18
dalendrk
Use distributive property: a(b +/- c) = ab +/ ac.

(x - 9)(x + 2) = (x)(x) + (x)(2) - (9)(x) - (9)(2) = x² + 2x - 9x - 18

= x² -7x -18