[tex](x + 1)(5x + 6) - (5x - 7)(x + 1) = [/tex]


Răspuns :

(x+1)(5x+6)-(5x-7)(x+1)=
dam factor comun pe (x+1)
(x+1)(5x+6-5x+7)=
(x+1)×13=
13x+13
sau 5x^2+6x+5x+6-5x^2-5x+7x+7=
13x+13