Упростите вырожение
a) (x-4) ^2-(x+1) (x+2)
б) 5(a+b) ^2-10ab

Ответ:

a) (x-4)²-(x+1)(x+2)=(х-4)(х-4)-(х+1)(х+2)=(х²-4х-4х+16)-(х²+2х+х+2)=х²-8х+16-(х²+3х+2)=х²-8х+16-х²-3х-2=х²-х²-8х-3х+16-2= -11х+14

б) 5(a+b)²-10ab=5(a+b)(a+b)-10ab=5*(a²+ab+ab+b²)-10ab=5*(a²+2ab+b²)-10ab=5a²+10ab+5b²-10ab=5a²+5b²+10ab-10ab=5a²+5b²