√5•(4√75-√125)

First, simplify inside the parentheses:

4√75 = 4•5•√3 = 20√3
√125 = √(25•5) = 5√5

Now plug back into the original expression:

√5•(20√3 - 5√5)

Now distribute the √5:

= 20√15 - 5√25
= 20√15 - 5•5
= 20√15 - 25

So, √5•(4√75-√125) simplifies to 20√15 - 25.