How do you simplify 5 square root of 8 times square root 18?

2 Answers
Jul 19, 2015

Answer:

Use #sqrt(ab) = sqrt(a)sqrt(b)# (for #a, b >= 0#) to find:

#5sqrt(8)sqrt(18) = 60#

Explanation:

If #a, b >= 0# then #sqrt(ab) = sqrt(a)sqrt(b)#

So:

#5sqrt(8)sqrt(18) = 5sqrt(8*18) = 5sqrt(144) = 5sqrt(12^2) = 5*12 = 60#

Jul 19, 2015

Answer:

Try and get the squares out of the root

Explanation:

#5*sqrt8*sqrt18=5*sqrt(8*18)#

Since #8=2^3and18=2*3^2#

#=5*sqrt(2^3*2*3^2)=5*sqrt(2^4*3^2)#

#=5*sqrt((2^2)^2)*sqrt(3^2)=5*2^2*3=60#