Question

please explain it to me correctly

Answer 1

anything having ^2 can be taken out of root so for 1st one
a^2 becomes a and √4 is equal to 2
similarly its done for b

Answer 2

in a) √ 4= 2 and √a^2 = a therefore they are taken out of the root and we cannot find the root of a therefore it is kept as it is.

in b) √9=3 and b^7 is been split up and thereby b^ 3 is taken out and as we cannot find the root of b it is kept as it is.