(3а+5в)² = (9а²+30ав+25в²)
(2в+4)² = (4в²+16в+16)
(х-3у)² = (х²-6ху+9у²)
(5в-3х)² = (25в²-30вх+9х²)
(а+3в)² = (а²+6ав+9в²)
