=`((sqrt(5) + sqrt(3))/(sqrt(5) - sqrt(3)))`

=`((sqrt(5) + sqrt(3)))/((sqrt(5) - sqrt(3))) x ((sqrt(5) + sqrt(3)))/((sqrt(5) + sqrt(3)))`

=`((sqrt(5) + sqrt(3))^2)/(5-3)`

=`(5 + 3 +2 sqrt(5) xx sqrt(3))/2`

=`(8 + 2sqrt(15))/2`

=`(4 + sqrt(15))`

=(4 + 3.8729)

=7.8729

The sum decimal places in the numerator and the denominator of the redicand being the same, we may remove the decimal places
`:.` Given Expression = `sqrt ((36 xx 25 xx 49)/(81 xx 16 xx 64))`

=`((6 xx 5 xx 7)/(9 xx 4 xx 8))`

=`35/48`

Resolving 2744 as the product of prime factors, we get:
2744 = `2^3` x `7^3`. 
`:.` `2744^((1/3))` = (2 x 7)
=14