Câu hỏi 7Nếu $t=\dfrac1{1-\sqrt[4]{2}},$ thì $t$ bằng$(1-\sqrt[4]{2})(2-\sqrt2)$$(1-\sqrt[4]{2})(1+\sqrt2)$$(1+\sqrt[4]{2})(1-\sqrt2)$$(1+\sqrt[4]{2})(1+\sqrt2)$$-(1+\sqrt[4]{2})(1+\sqrt2)$