What is the product of Seven square root eight times four square root five? Simplify your answer.

Twenty eight radical ten
Fifty six radical two
Fifty six radical ten
Two hundred eighty radical four

Question

What is the product of Seven square root eight times four square root five? Simplify your answer.

Twenty eight radical ten
 Fifty six radical two
 Fifty six radical ten
 Two hundred eighty radical four

Vocaloid · Answer

first you would just multiply the square root parts together

mikewwe13 · Answer

7√8*4√5
=

Vocaloid · Answer

sqrt(A) * sqrt(B) = sqrt(A*B)
sqrt(8) * sqrt(5) = ?

nolegirl24 · Answer

40?

nolegirl24 · Answer

Wait what?!?!?

Vocaloid · Answer

good, sqrt(40)

now we just multiply the non-radical parts to get 7 * 4 =  28

Vocaloid · Answer

now we go back to our sqrt(40) and see if we can factor out any perfect squares

Vocaloid · Answer

40 = 4*10

sqrt(40) = sqrt(4)*sqrt(10)

sqrt(4) = ?

nolegirl24 · Answer

square root of 4 is 2

Vocaloid · Answer

good, so sqrt(40) = sqrt(4)*sqrt(10) = 2*sqrt(10)

so let's put everything together

28* 2*sqrt(10) = 56sqrt(10) = C