№1
а) (2+b)(3b+2) = 6b+4+3b²+2b = 3b²+8b+4
б) (5b-b²)(2+3b) = 10b+15b²-2b²-3b³ = -3b³+13b²+10b
в) (2-b)(3-5b) = 6-10b-3b+5b² = 5b²-13b+6
г) (-3b-4)(2b-5) = -6b²+15b-8b+20 = -6b²+7b+20
№2
а) 9-(3+a)(2a+3) = 9- (6a+9+2a²+3a) = 9-(2a²+9a+9) = 9-2a²-9a-9 = 2a²-9a
б) 4a³+(a-a²)(3+4a) = 4a³+(3a+4a²-3a²-4a³) = 4a³+3a+a²-4a³ = a²+3a
в) (1-2x)(2+x)+(1-x)(2-2x) = (2+x-4x-2x²)+(2-2x-2x+2x²) = -2x²-3x+2+2x²-4x+2 = -7x+4
г) (x-3)(x-4)-(x-5)(x-2) = (x²-4x-3x+12)-(x²-2x-5x+10) = x²-7x+12-(x²-7x+10) = x²-7x+12-x²+7x-10 = 2
№3
а) 14x+7x² = 7x(2+x)
б) x(x-4)-5(x-4) = (x-4)(x-5)
№4
а) 2(x-3)+x²-3x = 2(x-3)+x(x-3) = (x-3)(2+x)
б) 3x-6-x(x-2) = 3(x-2)-x(x-2)=(x-2)(3-x)
в) x³+4x²-3x-12 = (x³+4x²)-(3x+12) = x²(x+4)-3(x+4) = (x+4)(x²-3)
г) x³-5x²-3x+15 = (x³-5x²)-(3x-15) = x²(x-5)-3(x-5) = (x-5)(x²-3)