SOLUTION: A rectangle's length is 20 less than 3 times its width. The perimeter of the rectangle is 80. What are the dimensions of the length and the width? I'm pretty sure that the answe

Question 208617: A rectangle's length is 20 less than 3 times its width. The perimeter of the rectangle is 80. What are the dimensions of the length and the width?
I'm pretty sure that the answer is 25 x 15 from trial and error, but I do not know how to solve it algebraically.
Answer by nyc_function(2741) (Show Source): You can put this solution on YOUR website!

Let length = 3x - 20
Let width = x
The perimeter is 80
Use the formula: P = 2L + 2W as step one.
Here is the set up:
80 = 2(3x - 20) + 2(x)
When you find x, this will be your width. Then go back to 3x - 20, plug your value for x and simplify to find your length.
Can you finish now?

RELATED QUESTIONS
the length of a rectangle is 7 inches less than 3 times its width. if the perimeter of... (answered by mananth)

The perimeter of a rectangle is 80 inches. The length of the rectangle is 8 less then... (answered by checkley77)

A rectangle has a perimeter of 30 inches, its length is one less than 3 times its width.... (answered by ewatrrr)

The length of a rectangle is 2cm more than 3 times its width. If the perimeter of the... (answered by josgarithmetic)

the width of a rectangle is 15 less than 3 times its length. if the perimeter is 26, what (answered by TimothyLamb)

The length of a rectangle is three times its width. It's perimeter is 80 m. What are the... (answered by CubeyThePenguin)

The length of a rectangle is 4 cm less than 3 times the width. The perimeter is 88 cm.... (answered by unlockmath)

The length of a rectangle is 4 cm less than 3 times the width. if the perimeter is 88 cm, (answered by rfer)

the perimeter of a rectangle is 48". The length is 3" less than twice its width. What... (answered by checkley79)

The length of a rectangle is 2 centimeters less than twice its width. The perimeter of... (answered by EMStelley,CharlesG2)