Question

1 / (4- 3 căn bậc hai 2) - 1 / (4+3 căn bậc hai 2) )

Answer 1

\(\dfrac{1}{4-3\sqrt{2}}-\dfrac{1}{4+3\sqrt{2}}\) thế này ak b?

\(\dfrac{1}{4-3\sqrt{2}}-\dfrac{1}{4+3\sqrt{2}}=\dfrac{4+3\sqrt{2}}{\left(4-3\sqrt{2}\right)\left(4+3\sqrt{2}\right)}-\dfrac{4-3\sqrt{2}}{\left(4-3\sqrt{2}\right)\left(4+3\sqrt{2}\right)}=\dfrac{4+3\sqrt{2}-4+3\sqrt{2}}{4^2-\left(3\sqrt{2}\right)^2}=\dfrac{6\sqrt{2}}{-2}=-3\sqrt{2}\)

Answer 2

bt\(=\dfrac{4+3\sqrt{2}-4+3\sqrt{2}}{-2}=\dfrac{2\cdot3\sqrt{2}}{-2}=-3\sqrt{2}\)