Question

plz give me ans...............

Answer 1

By taking the root common, we know the following:
√30/√6 = √5
√140/√28 = √5
√55/√99 = √5/3

put it in the given equation

=2√30/√6 -3√140/√28 + √55/√99
= 2 √5 -3 √5 + √5/3
= √5(2-3+1/3)
= √5(6-9+1)/3
=-2√5/3

Answer 2

we can also write
√30 = √3×√10
√140 = √28×√5
√55 = √11×√5
√99 = √11×√9

2√30/√6 - 3√140/√28 + √55/√99

= (2√3×√10/√2×√3) - (3√28×√5/√28) + (√11×√5/√11×√9)

= 2√5 - 3√5 + √5/√9

= (2-3)√5 + √5/3

= -1√5 + √5/3

(LCM of √3 and 1 is √3)

= (-3√5+√5)/3

= (-3+1)√5/3

(take common as √5)

= -2√5/3