Question

1)(10-7у)×(7у+10); (2+а)×(4-2а+а^2); можно быстрее

Answer 1

1) 10*7y+10*10-7y*7y-7y*10=70y+100-49y^2-70y=100-49y^2
2) 2*4-2*2a+2*a^2+4*a-2a*a+a*a^2=8-4a+2a^2+4a-2a^2+a^3=8+a^3