Question

Выражения: 1- 3a +2a( a - 3) 2- 5a(a-2b) - 2b (4a+b) 3- 4x - 3x(x+1) 4- 2x^2 (x+1) + x^2 (x-3) 5- (x-4)(x+5) 6- (x-1)(2x+3) 7- (x+ + 2) 8- (3x-2)(x-1)

Answer 1

$1) 3a+2a(a-3)=3a+2 a^{2} -6a=2a^{2} -3a \\ 2)5a(a-2b)-2b(4a+b)=5a^{2} -10ab-8ba-2b^{2} =5a^{2} -18ab-2b^{2} \\ 3)4x-3x(x+1)=4x-3 x^{2} -3x=x-3 x^{2} \\ 4)2 x^{2} (x+1)+ x^{2} (x-3)=2 x^{3} +2 x^{2} + x^{3} -3 x^{2} =3 x^{3} - x^{2} \\ 5)(x-4)(x+5)= x^{2} +5x-4x-20= x^{2} -x-20 \\ 6)(x-1)(2x+3)=2 x^{2} +3x-2x-3=2 x^{2} +x-3 \\ 7)(x+4)(-x+2)=- x^{2} +2x-4x+8=- x^{2} -2x+8 \\ 8)(3x-2)(x-1)=3 x^{2} -3x-2x+2=3 x^{2} -5x+2$