1-2 times the square root of ten divided by 4 + the square root of ten

$$\\1-2\times\frac{\sqrt{10}}{4}+\sqrt{10}\\\\
=1-\frac{\sqrt{10}}{2}+\frac{2\sqrt{10}}{2}\\\\
=1+\frac{\sqrt{10}}{2}\\\\
=\frac{2+\sqrt{10}}{2}\\\\$$

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