Tutor profile: Kurt G.

The length of a rectangle is five times its width. If the area of the rectangle is 405 ft^2, find its perimeter.

Using: l=length of the rectangle w=width of the rectangle we know... A=l*w l=5*w We can then substitute the equation we made for "l" in terms of w into our Area equation and solve using the area of the rectangle that was given in the problem. Solving this equation will give us a width of 9 ft. Then, substituting back into our length equation, we know that the length is 45. Using our perimeter formula: P=2l+2w we can find that: P=108ft

What is 20% of 80?

First, we can take an easier percentage, such as 10%. 10% of 80 is 8, and you get to that answer by dropping a zero. To get to 20%, we simply double the answer we just got. 8 multiplied by 2 is 16. So 20% of 80 is 16.

Simplify: 12x^3 - 3(2x^3 + 4x -1) - 5x + 7

First, we need to expand the above equation. Once expanded, we can simplify by combining like terms to reach the solution of 6x^3 -17x + 10.