Question

Thực hiện các phép nhân phân thức sau:

a) \(\dfrac{{4y}}{{3{x^2}}} \cdot \dfrac{{5{x^3}}}{{2{y^3}}}\)                 

b) \(\dfrac{{{x^2} - 2x + 1}}{{{x^2} - 1}} \cdot \dfrac{{{x^2} + x}}{{x - 1}}\)                       

c) \(\dfrac{{2x + {x^2}}}{{{x^2} - x + 1}} \cdot \dfrac{{3{x^3} + 3}}{{3x + 6}}\)

Answer 1

\(a,=\dfrac{4y.5x^3}{3x^2.2y^3}=\dfrac{20x^3y}{6x^2y^3}=\dfrac{10x}{3y^2}\\ b,=\dfrac{\left(x-1\right)^2.x\left(x+1\right)}{\left(x-1\right)\left(x+1\right)\left(x-1\right)}=\dfrac{\left(x-1\right)^2.x.\left(x+1\right)}{\left(x-1\right)^2.\left(x+1\right)}=x\)

\(c,=\dfrac{x\left(2+x\right).3\left(x^3+1\right)}{\left(x^2-x+1\right).3.\left(x+2\right)}=\dfrac{3x.\left(x+2\right).\left(x+1\right)\left(x^2-x+1\right)}{\left(x^2-x+1\right).3\left(x+2\right)}=x\left(x+1\right)\)