4th Edition Guide 1 PG. 83 Q-14

[chipreno]

I went over the answer and still was not able to understand how they got 2xy(square root)y

[tim]

(for reference, this one is from the Number Properties guide)

adding the expressions under the radical we get 4 x^2 y^3. since these are all multiplied together, we can put a separate radical over each piece: root(4) = 2 and root(x^2) = x (since they told us x is positive). as for the y^3, break it into y^2*y and put a radical over each part. root(y^2) = y, and we are left with a root(y) we can't simplify. what we have left is 2*x*y*root(y)