Answer: 2m^2n.\sqrt{5}
Step-by-step explanation: Factor 20 into its prime factors
20 = 22 • 5
To simplify a square root, we extract factors which are squares, i.e., factors that are raised to an even exponent.
Factors which will be extracted are :
4 = 22
Factors which will remain inside the root are :
5 = 5
To complete this part of the simplification we take the squre root of the factors which are to be extracted. We do this by dividing their exponents by 2 :
2 = 2
At the end of this step the partly simplified SQRT looks like this:
2 • sqrt (5m4n3)
Rules for simplifing variables which may be raised to a power:
(1) variables with no exponent stay inside the radical
(2) variables raised to power 1 or (-1) stay inside the radical
(3) variables raised to an even exponent: Half the exponent taken out, nothing remains inside the radical. examples:
(3.1) sqrt(x8)=x4
(3.2) sqrt(x-6)=x-3
(4) variables raised to an odd exponent which is >2 or <(-2) , examples:
(4.1) sqrt(x5)=x2•sqrt(x)
(4.2) sqrt(x-7)=x-3•sqrt(x-1)
Applying these rules to our case we find out that
SQRT(m4n3) = m2n • SQRT(n)
sqrt (20m4n3) =
2 m2n • sqrt(5n)
2 m2n • sqrt(5n)
