trong ngoặc cứ quy đồng (nhớ đặt đk a>0; a khác 1) rồi làm như bt
\(P=\left(\frac{1}{1-\sqrt{a}}-\frac{1}{1+\sqrt{a}}\right):\frac{\sqrt{a}}{\sqrt{a}-1}\)
\(P=\left(\frac{1+\sqrt{a}}{\left(1-\sqrt{a}\right)\left(1+\sqrt{a}\right)}-\frac{1-\sqrt{a}}{\left(1+\sqrt{a}\right)\left(1-\sqrt{a}\right)}\right).\frac{\sqrt{a}-1}{\sqrt{a}}\)
\(P=\left(\frac{1+\sqrt{a}-1+\sqrt{a}}{1-a}\right).\frac{\sqrt{a}-1}{\sqrt{a}}\)
\(P=\left(\frac{2\sqrt{a}}{1-a}\right).\frac{\sqrt{a}-1}{\sqrt{a}}\)
\(P=\frac{2\sqrt{a}.\left(\sqrt{a}-1\right)}{\sqrt{a}.\left(1-a\right)}\)
\(P=\frac{2\left(\sqrt{a}-1\right)}{1-a}\)
vay \(P=\frac{2\left(\sqrt{a}-1\right)}{1-a}\)
\(P=\left(\frac{1}{1-\sqrt{a}}-\frac{1}{1+\sqrt{a}}\right):\frac{\sqrt{a}}{\sqrt{a}-1}\)
\(P=\left(\frac{1+\sqrt{a}}{1-a}-\frac{1-\sqrt{a}}{1-a}\right):\frac{\sqrt{a}}{\sqrt{a}-1}\)
\(P=\frac{2\sqrt{a}}{1-a}:\frac{\sqrt{a}}{\sqrt{a}-1}\)
\(P=\frac{2\sqrt{a}}{1-a}\times\frac{\sqrt{a}-1}{\sqrt{a}}\)
\(P=-\frac{2\sqrt{a}}{a-1}\times\frac{\sqrt{a}-1}{\sqrt{a}}\)
\(P=-\frac{2}{\sqrt{a}+1}\)
bạn có thể làm kĩ hơn ko. Bạn rút gọn giúp mình đi. mình dở toán lắm
