1) = х(2 +3у)
2)= 5a(b +2a)
3)=ху(у² +5ху -3х)
4)= (b-c)(a-c)
5)=(4a +4b) + (by +ay) = 4(a +b) +y(b +a) = (a +b)(4 +y)
6) = (2a +b)²
7) = (2x-1)(2x +1)
8)=(7x -11a)(7x +11a)
9) = 3(x² -4) = 4(x -2)(x +2)
10) = (a³ + 8b³) + (a² -2ab +4b²) = (a +2b)(a² -2ab +4b²)+(a² -2ab +4b²)=
=(a² -2ab +4b²)(a +2b +1)