1) (6-а)²= 6²-2×6а+а²= 36-12а+а²;
2) (Зх+4)²= (3х)²+2×3х×4+4²= 9х²+24х+16;
3) (5у+а)(5у-а) = (5у)²-а²= 25у²-а².
1) (6-а)²= 6²-2×6а+а²= 36-12а+а²;
2) (Зх+4)²= (3х)²+2×3х×4+4²= 9х²+24х+16;
3) (5у+а)(5у-а) = (5у)²-а²= 25у²-а².