Consider √x = t
We get

It can be written as
dx = 2 √x dt
where dx = 2t dt
We can replace it in the equation
∫e√x dx = ∫et 2t dt
So we get
= 2 ∫t et dt
Consider the first function as t and second function as et

By integration w.r.t. t
= 2 (t et – ∫1. et dt)
We get
= 2 (t et – et) + c
Taking et as common
= 2 et(t – 1) + c
Substituting the value of t we get
= 2 e√x(√x – 1) + c