nhân đa thức với đơn thức a) 2 ( x – 3 ) + 3 ( x + 7 ) b) -5 ( x – 1 ) – 2 . ( x + 3 ) c) x . ( 2x – 1 ) + x ² . ( x – 2 ) d) -4x mũ 5 . ( x ³ – 4x ²

a, 2(x-3)+3(x+7)

= 2x-6+3x+21

= 5x+15

b, -5(x-1)-2(x+3)

= -5x+5-2x-6

= -7x-1

c, x(2x-1)+x²(x-2)

= 2x²-x+x³-2x²

= x³-x

d, $-4x^{5}$(x³-4x²+7x-3)

= $-4x^{8}$+$16x^{7}$-$28x^{6}$+$12x^{5}$ 

e, 4x(x²-x+1)-x(3x²-2x-5)

= 4x³-4x²+4x-3x³+2x²+5x

= x³-2x²+9x