Question

  giải giúp mình với

Câu 10. (3 đ) Thực hiện phép tính:

a) \(\frac{5x+9}{x+2} + \frac{2x+5}{x+2}\)

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

c) \(\frac{2x}{2x-5} - \frac{5}{5-2x}\)

Answer 1

a: \(\dfrac{5x+9}{x+2}+\dfrac{2x+5}{x+2}\)

\(=\dfrac{5x+9+2x+5}{x+2}=\dfrac{7x+14}{x+2}=\dfrac{7\left(x+2\right)}{x+2}\)

=7

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

\(=\dfrac{2\left(x-1\right)}{x-1}\cdot\dfrac{x}{x^2}=\dfrac{2}{x}\)

c: \(\dfrac{2x}{2x-5}-\dfrac{5}{5-2x}=\dfrac{2x}{2x-5}+\dfrac{5}{2x-5}=\dfrac{2x+5}{2x-5}\)

Answer 2

a: =5x+9+2x+5x+2=7x+14x+2=7(x+2)x+2=5x+9+2x+5x+2=7x+14x+2=7(x+2)x+2

=7

b: =2(x−1)x−1⋅xx2=2x=2(x−1)x−1⋅xx2=2x

c: