Question

 

giúp mình câu 3 với 

Answer 1

1: Khi x=16 thì \(A=\dfrac{3-4}{4-2}+1=\dfrac{-1}{2}+1=\dfrac{1}{2}\)

2: \(P=\dfrac{x+2\sqrt{x}-x+\sqrt{x}+2-2\sqrt{x}-7}{x-4}:\dfrac{3-\sqrt{x}+\sqrt{x}-2}{\sqrt{x}-2}\)

\(=\dfrac{\sqrt{x}-5}{x-4}\cdot\dfrac{\sqrt{x}-2}{1}=\dfrac{\sqrt{x}-5}{\sqrt{x}+2}\)

3: |P|>P

=>P<0

=>\(\sqrt{x}-5< 0\)

=>0<=x<25

=>\(x\in\left\{2;3;5;7;11;13;17;19;23\right\}\)