I have 2 questions that I do not understand can someone help?

Question

1. (radical 20 over five) minus (one over radical 5)

2. (radical75a^2 over radical 5)

Answer 1

Prob 1:
√(20)/5 – 1/√(5)
√(4*5)/5 – 1/√(5) (Factoring the first term.)
2√(5)/5 – 1/√(5) (Take the square root of 4 outside the radical.)
2√(5)/5 – √(5)/5 (Multiply numerator and denominator of second term by radical 5.)
[(2-1) √(5)]/5 (Collect like radical terms in the numerator.)
√(5)/5 (Do the subtraction in the numerator.)

Prob 2:
√(75a²)/ √(5)
√(75a²/5) (Move both terms into the same radical.)
√(25a²) (Divide)
5a (Take the square root of both factors.)

Hope this helps.
FE

Answer 2

1) = 2sqrt(5)/5 - sqrt(5)/5 = sqrt(5)/5 = 1/sqrt(5)

2) 5a*sqrt(3)/sqrt(5) = a * sqrt(5)sqrt(3)