(7х - 1) (2+х)= (х-4) (х+4)

х(8-3х)= (5х-1) в кв

(7х-1)(2+х)=(х-4)(х+4)14х+7х^2-2-х=х^2-1613х+7х^2-2-х^2+16=05х^2+13х+14=0х(8-3х)=(5х-1)^28х-24х^2=25х^2-10х+18х-24х^2-25х^2+10х-1=0-49х^2+2х-1=049х^2-2х+1=0