Question

[pthuong]

\(\dfrac{1}{2}\left(\sqrt{6}+\sqrt{5}\right)^2-\dfrac{1}{4}\sqrt{120}-\dfrac{\sqrt{15}}{2}\)

Answer 1

[Dora]

`1/2(\sqrt{6}+\sqrt{5})^2-1/4\sqrt{120}-\sqrt{15}/2`

`=1/2 .(6+5+2\sqrt{30})-1/4 \sqrt{2^2 .30}-\sqrt{15}/2`

`=11/2+\sqrt{30}-1/2 \sqrt{30}-\sqrt{15}/2`

`=[11+2\sqrt{30}-\sqrt{30}-\sqrt{15}]/2`

`=[11+\sqrt{30}-\sqrt{15}]/2`

Answer 2

[Akai Haruma]

Lời giải:

$\frac{1}{2}(\sqrt{6}+\sqrt{5})^2-\frac{1}{4}\sqrt{120}-\frac{\sqrt{15}}{2}$

$=\frac{1}{2}(11+2\sqrt{30})-\frac{1}{2}\sqrt{30}-\frac{\sqrt{15}}{2}$

$=\frac{11}{2}+\frac{\sqrt{30}}{2}-\frac{\sqrt{15}}{2}$