Question

b) ạ

Answer 1

b: \(A=\dfrac{2x_1-2x_2}{x_1x_2}\cdot\left(x_1-x_2\right)=\dfrac{2\left(x_1-x_2\right)^2}{x_1x_2}\)

\(=\dfrac{2\cdot\left[\left(x_1+x_2\right)^2-4x_1x_2\right]}{x_1x_2}\)

\(=\dfrac{2\cdot\left[11^2-4\cdot5\right]}{5}=\dfrac{2}{5}\cdot\left(121-20\right)=91\cdot\dfrac{2}{5}=\dfrac{182}{5}\)