Factor y^3 to y^2•y because y^2•y=y^3 and the radical indicates that we must take the square root, not the cube root of y. y^2 is a perfect square, which will be helpful.
√y^3 = √y^2•y
√y^2•y = y•√y
Because the square root of y cubed simplifies to: y•√y, the two terms being multiplied are the same, so we can simply multiply them:
(y•√y)(y•√y)
The Associative Property of Multiplication states that we can arrange the terms in any order without affecting their product:
(y•y)(√y•√y)
Simply, but remember the exponent rules: a^n•a^m=a^n+m
y^2•√y^2
y^2•y
y^3 is the answer.