The length of a rectangle is one more than three times the w

The length of a rectangle is one more than three times the width. What are the dimensions of the rectangle if its area is 30?

Solution

L=3w+1
Area = L times w
30 = L times w
30 = (3w+1)*w
30 = (3w^2+w)
10 = w^2+(1/3)w
10=(w+(1/6))^2-(1/36)
10+(1/36)=(w+(1/6))^2
3+(1/6)=w+(1/6)
3=w
L=10.