Question

\(\frac{2\text{x}^2-20\text{x}+50}{3\text{x}+3}.\frac{x^2-1}{4\left(x-5\right)^3}=?\)

Answer 1

ĐKXĐ:

\(3x+3\ne0\)và \(x-5\ne0\)

<=>\(3x\ne-3\)và \(x\ne5\)

<=>\(x\ne-1\)và \(x\ne5\)

\(\frac{2x^2-20x+50}{3x+3}.\frac{x^2-1}{4\left(x-5\right)^3}=\frac{2\left(x^2-10x+25\right)}{3\left(x+1\right)}.\frac{\left(x+1\right)\left(x-1\right)}{4\left(x-5\right)^3}\)

\(\frac{2\left(x-5\right)^2}{3\left(x+1\right)}.\frac{\left(x+1\right)\left(x-1\right)}{4\left(x-5\right)^3}=\frac{x-1}{6\left(x-5\right)}=\frac{x-1}{6x-30}\)