What is 5 the square root of 8 • 4 the square root of 7?

1 Answer
Sep 28, 2015

Answer:

Multiply the numbers and the squares separately and and remember that #sqrta*sqrtb=sqrt(a*b)#

Explanation:

#5*sqrt8*4*sqrt7=5*4*sqrt8*sqrt7=20*sqrt(8*7)=20sqrt56#

We're not done yet, because #56=4*14=2^2*14#
and we can take the square out of the root:

#=20*sqrt(2^2*14)=20*sqrt(2^2)*sqrt14=20*2*sqrt14#

Final answer: #40sqrt14#