6х²-(5х+1)(х+3)=(х+3)(х-5)+2
Плиз !!!

6х²-(5х²+15х+х+3) = 2+(х²-5х+3х-15)6х²-5х²-15х-х-3 = 2+х²-5х+3х-15х²-16х-3=х²-2х-13х²-х² -16х+2х = -13+3-14х=-10  | * (-1)14х=10х = 5/7