Question

1.Tính 

a, 5x^3yz . (-7x^2y^3)

b, 6x(x-5) -x(6x+3)

c, (x-9)(x^2-2x-1)

2.Cho A (x)=10-2x+4x^3-5x^2

          B(x)=-10x^3-5x+6x^2-20

Tính A(x)+B(x); A(x)-B(x)

3.Tìm nghiệm

a,M(x)= 5x+20

b,N(x)=100x^2-49

c,P(x)=3x-15

Answer 1

Bài 1;

a)\(5x^3yz.\left(-7x^2y^3\right)=-35.x^5y^4z\)

b)\(6x\left(x-5\right)-x\left(6x+3\right)=6x^2-30x-6x^2-3x=-33x\)

c) \(\left(x-9\right)\left(x^2-2x-1\right)=x^3-2x^2-x-9x^2+18x+9=x^3-11x^2+17x+9\)