1. 2х³-3у = 2(-1)³ - 3(-2) = -2+6 = 4
2. а) -4х³(х²-3х+2) = -4х⁵+12х⁴-8х³
б) (1-х)(2у+х) = 2у+х-2ху-х²
в) (5х-4)² = 25х²-40х+16
3. а) 3а(a-b)+b(2a-b) = 3a²-3ab+2ab-b² = 3a²-ab-b²
б) (с-3)²-3с(с-2) = с²-6с+9-3с²+6с = -2с²+9
в) (3х+1)(4х-2)-6(2х-1)²+14 = 12х²-6х+4х-2-24х²+24х-6+14 = -12х²+22х+6
4. ((а²+1)²-(а²-1)²)/a² = ((a²+1-a²+1)(a²+1+a²-1))/a² = (2*2a²)/a² = 4
5. 3(12xy-5xz)-5(10xy-6xz+2yz) = 36xy-15xz-50xy+30xz-10yz = -14xy+15xz-10yz