Question

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

Answer 1

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`