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)![(3a-b)(2b+4a)=6ab-2b^2+12a^2-4ab=12a^2+2ab-2b^2](/tpl/images/0062/2364/750a7.png)
2)![(4y-5x)^2=(4y)^2-2\cdot4y\cdot5x+(5x)^2=25x^2-40xy+16y^2](/tpl/images/0062/2364/c0902.png)
(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