Question

hi plz solve the underlined part. need clarification.​

Answer 1

They've written a^2 + 9a^2 = 10a^2 in the further step

Then, since 10a^2 is raised to the power of 3/2

this means that first we need to find the root of 10a^2 and then cube it
So, root of 10a^2 = √10 * a
Now, cubing this
= (√10)^3 * a^3 = 10√10a^3
So,
a^3 in the numerator and the denominator cancels up, and 2*10√10 = 20√10 as shown in the next step.

Hope it's clear now !
Do comment down if you've any doubts?