Question

[Hoàng Huy]

thực hiện phép tính 

\(\dfrac{x^2-50}{3x^2-9x}:\dfrac{2x^2+10x}{x^2-9}\)

\(\dfrac{-3x^2}{2x+1}:\left(-\dfrac{9}{4x^2-1}\right)\)

Answer 1

[Huỳnh Thị Thanh Ngân]

\(\dfrac{x^2-50}{3x^2-9x}\div\dfrac{2x^2+10x}{x^2-9}\)

\(\Leftrightarrow\dfrac{x^2-50}{3x\left(x-3\right)}\div\dfrac{2x^2+10x}{\left(x-3\right)\left(x+3\right)}\)

MTC: 3x(x-3)(x+3)

\(\dfrac{(x^2-50)\left(x+3\right)}{3x\left(x-3\right)\left(x+3\right)}\div\dfrac{3x(2x^2+10x)}{3x\left(x-3\right)\left(x+3\right)}\)

\(\Rightarrow\)(x²-50)(x+3):3x(2x²+10x)

\(\Rightarrow\)(x³+3x²-50x-150):6x³+30x²