1)
2)
(3a-b)(2b+4a)=6ab+12a^{2}-2b^{2}-4ab=2ab+12а^{2}-2b^{2}
(4y-5x)^{2}=16y^{2}-40xy+25x^{2} 100% гарантия
1)
2)
(3a-b)(2b+4a)=6ab+12a^{2}-2b^{2}-4ab=2ab+12а^{2}-2b^{2}
(4y-5x)^{2}=16y^{2}-40xy+25x^{2} 100% гарантия