Question

[Đừng gọi tôi là Jung Hae Ri]

Thực hiện phép tính:

\(a,\dfrac{x^2+3x+9}{2x+10}.\dfrac{x+5}{x^3-27}\)

\(b,\left(\dfrac{6x+1}{x^2-6x}+\dfrac{6x-1}{x^2+6x}\right)\left(\dfrac{x^2-36}{x^2+1}\right)\)

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(=\dfrac{x^2+3x+9}{2\left(x+5\right)}\cdot\dfrac{\left(x+5\right)}{\left(x-3\right)\left(x^2+3x+9\right)}=\dfrac{1}{2\left(x-3\right)}\)

b: \(=\dfrac{\left(6x+1\right)\left(x+6\right)+\left(6x-1\right)\left(x-6\right)}{x\left(x-6\right)\left(x+6\right)}\cdot\dfrac{\left(x-6\right)\left(x+6\right)}{x^2+1}\)

\(=\dfrac{6x^2+37x+6+6x^2-37x+6}{x}\cdot\dfrac{1}{x^2+1}=\dfrac{12}{x}\)