\(\Rightarrow\left(a+b\right)^2=\frac{9ab}{2};\left(a-b\right)^2=\frac{ab}{2}\)
Suy ra: \(\frac{2b}{a-b}+1=\frac{a+b}{a-b}=\frac{\frac{9ab}{2}}{\frac{ab}{2}}=9\)
\(\Rightarrow\frac{2b}{a-b}-1=\frac{a+b}{a-b}=\frac{\sqrt{\frac{9ab}{2}}}{\sqrt{\frac{ab}{2}}}=3\)