Everett built a rectangular concrete patio that was four times as long as it was wide.  If the perimeter of the patio was 100 feet, what was the length of the patio, in feet?
Let's make "x" be the width of the patio.
Then the length of the patio would be 4*x.
And the perimeter of the patio would be the sum of all four sides, or x+(4*x)+x+(4*x)=100 feet.
This simplifies to 10x=100 feet.
And the width of the patio x=<<10=10>>10 feet.
And the length of the patio is 4*x = 4*10 = 40 feet.
#### 40