How would i go about doing this math problem

Multiply and simplify. Assume that all variables are positive.

√8y^5 * √40y^2

√320y^7
= √64y^6 •√5y
= 8y³•√5y

you can put the root together so
√8y^5*40y^2=√320y^7=8y^5√5

sqrt (4*2*y^2*y^2*y) sqrt (4*10*y^2) =
(2y*y sqrt 2y)(2y sqrt 10) =
(2y^2 sqrt 2y)(2y sqrt 10) =5
4y^3 sqrt (2y*10) =
4y^3*2 sqrt 5 =
8y^3 sqrt

√8y^5 * √40y^2
= 128√2y^(5/2) * 40y
= 5120√2y^(7/2)

Pay attention in class.