`A=\sqrt5(\sqrt20 -3)+\sqrt45`
`A=\sqrt5(2\sqrt5-3)+3\sqrt5`
`A=2.5-3\sqrt5+3\sqrt5`
`A=10`
`B=(\sqrt20-\sqrt45+3\sqrt5).\sqrt5`
`B=(2\sqrt5-3\sqrt5+3\sqrt5).\sqrt5`
`B=2\sqrt5.\sqrt5`
`B=2.5`
`B=10`
`C=\sqrt{\sqrt2(\sqrt2-2)+(\sqrt2+1)}`
`C=\sqrt{2-2\sqrt2+\sqrt2+1}`
`C=\sqrt{3-\sqrt2}`