1. 1) (2y+1)(5y-6)
10y²-12y+5y-6
10y²-7y-6
2)(3a-b)(2a-7b)
6a²-21ab-2ab+7b²
6a²-23ab+7b²
3)(a-4b)(a²+3ab-6b²)
a³+3a²b-6ab²-4a²b-12ab²+24b³
a³-a²b-18ab²+24b³
4)a(4a-5)(2a+3)
(4a²-5a)(2a+3)
8a³+12a²-10a²-15a
8a³+2a²-15a
2. 1) (x+y)(2x-y)(3x+y)
(2x²-xy+2xy-y²)(3x+y)
(2x²+xy-y²)(3x+y)
6x³+2x²y+3x²y+xy²-3xy²-y³
6x³+5x²y-2xy²-y³
2) (x²-3x+1)(x²+3x+1) (a-b)(a+b)=a²-b²
(x²+1)²-9x²
x^4 + 2x²+1-9x²
x^4-7x²+1