Question

Thực hiện phép nhân

a) x^3 (3x^2-x-1/2)

b) (5xy-x^2+y)2/5xy^2

c) (4x^3 -3xy^2+2xy)(-1/3x^2y)

Answer 1

\(a,x^3\left(3x^2-x-\dfrac{1}{2}\right)\)

\(=3x^5-x^4-\dfrac{1}{2}x^3\)

\(b,\left(5xy-x^2+y\right).\dfrac{2}{5xy^2}\)

\(=\dfrac{2}{y}-\dfrac{2x}{5y^2}+\dfrac{2}{xy}\)

\(c,\left(4x^3-3xy^2+2xy\right)\left(-\dfrac{1}{3}x^2y\right)\)

\(=-\dfrac{4x^5y}{3}+x^3y^3-\dfrac{2x^3y^2}{3}\)