`b)`
`\sqrt(8+\sqrt(60))+\sqrt(45)-\sqrt(12)`
`=\sqrt(3+5+2\sqrt(5).\sqrt(3))+3\sqrt(5)-2\sqrt(3)`
`=\sqrt((\sqrt(5)+\sqrt(3))^2)+3\sqrt(5)-2\sqrt(3)`
`=\sqrt(5)+\sqrt(3)+3\sqrt(5)-2\sqrt(3)`
`=4\sqrt(5)-\sqrt(3)`
`c)`
`\sqrt(x+4\sqrt(x-4))`
`=\sqrt(x-4)+2.2\sqrt(x-4)+4)`
`=\sqrt((\sqrt(x-4)+2)^2)`
`=\sqrt(x-4)+2`
`d)`
`\sqrt(5)+\sqrt(11-2\sqrt(30))`
`=\sqrt(5)+\sqrt(5+6-2\sqrt(5).\sqrt(6))`
`=\sqrt((\sqrt(6)-\sqrt(5))^2)+\sqrt(5)`
`=\sqrt(6)-\sqrt(5)+\sqrt(5)`
`=\sqrt(6)`
`e)`
`\sqrt(9-4\sqrt(5))-\sqrt(9+4\sqrt(5))`
`=\sqrt(5+4-2.2\sqrt(5))-\sqrt(5+4+2.2\sqrt(5))`
`=\sqrt((\sqrt(5)-2))^2-\sqrt((\sqrt(5)+2))^2`
`=\sqrt(5)-2-\sqrt(5)-2`
`=-4`
`
