7)
`G=(\sqrt15+2\sqrt3)^2+12\sqrt5`
`G=((\sqrt15)^2+12\sqrt5+(2\sqrt3)^2)+12\sqrt5`
`G=15+12\sqrt5+12+12\sqrt5`
`G=24\sqrt5+27`
8)
`H=\sqrt20.(2-3\sqrt5)+(1-2\sqrt5)^2+2\sqrt45`
`H=2\sqrt20-30+(1-4\sqrt5+(2\sqrt5)^2)+2\sqrt45`
`H=2\sqrt20-30+1-4\sqrt5+20+2\sqrt45`
`H=4\sqrt5-4\sqrt5+6\sqrt5-9`
`H=6\sqrt5-9`
$#CHÚC BẠN HỌC TỐT$