Kak reshit uravnenie i kak raskrit skobki esli (x-1)(x+2)=28

Question

Kak reshit uravnenie i kak raskrit skobki esli
(x-1)(x+2)=28

Answer 1

Х^2+2х-х-2=28
х^2+х=28+2
х^2+х=30
х^2+х-30=0
D=1+120=121=11
х=-1-11/2=-6   х=-1+11/2=5