Question

Giúp mk vs ạ

Answer 1

a: ĐKXĐ: x>=0; x<>3

\(M=\dfrac{x-x-6\sqrt{x}-9+x-6\sqrt{x}+9}{x-9}\)

\(=\dfrac{x-12\sqrt{x}}{x-9}\)

b: Thay x=25 vào M, ta được:

\(M=\dfrac{25-12\cdot5}{25-9}=\dfrac{-275}{16}\)