Question

How do you evaluate `2\sqrt { 15} ( 3+ \sqrt { 5} )?`

Answer 1

`2sqrt(15)(3+sqrt(5)) = 6sqrt(15)+2sqrt(75)`
`=6sqrt(5\times 3)+2sqrt(25\times 3)`
`= 6sqrt(5)sqrt(3)+10sqrt(3)`
`=sqrt(3)(6sqrt(5)+10)`

Now substitute values for `sqrt(5)` and `sqrt(3)`.
`= 1.732(6\times2.236+10)`
`=1.732\times23.416`
`=40.556` upto 3rd decimal precision