Answer:
[tex]x ^ { 4 } - 3 x ^ { 2 } - 10 = 0\\Let, t = x^{2} \\\rightarrow \: t^{2}-3t-10=0 \\\\\\t=\frac{-\left(-3\right)(+/-)\sqrt{\left(-3\right)^{2}-4\times 1\left(-10\right)}}{2} \\t=\frac{3(+/-)7}{2} \\\\So,\\t = 5 \: and \: -2\\\\Then,\\x = \sqrt{5} \: and \: -\sqrt{5}[/tex]
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