Question

a) Tìm x để N=\(\dfrac{1}{2}\)

b) Tìm x ∈ \(Z\) sao cho N ∈ \(Z\)

c) Tìm GTLN của N

Answer 1

Answer 2

a: Ta có: \(N=\dfrac{4\sqrt{x}-7}{x+\sqrt{x}-2}+\dfrac{2-\sqrt{x}}{\sqrt{x}-1}-\dfrac{2\sqrt{x}+1}{\sqrt{x}+2}\)

\(=\dfrac{4\sqrt{x}-7+4-x-2x+\sqrt{x}-1}{\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)}\)

\(=\dfrac{-3x+5\sqrt{x}-4}{x+\sqrt{x}-2}\)