Question

help me 

Answer 1

a: Khi x=25 thì \(A=\dfrac{2\cdot5-1}{5-1}=\dfrac{9}{4}\)

b: \(B=\dfrac{x+\sqrt{x}+3\sqrt{x}-3-6\sqrt{x}+4}{x-1}=\dfrac{x-2\sqrt{x}+1}{x-1}\)

\(=\dfrac{\sqrt{x}-1}{\sqrt{x}+1}\)

c: P=A*B\(=\dfrac{\sqrt{x}-1}{\sqrt{x}+1}\cdot\dfrac{2\sqrt{x}-1}{\sqrt{x}-1}=\dfrac{2\sqrt{x}-1}{\sqrt{x}+1}\)

P<1

=>P-1<0

=>(2căn x-1-căn x-1)/(căn x+1)<0

=>căn x-2<0

=>0<x<4

mà x nguyên và x<>1

nên x thuộc {2;3}