The perimeter of a rectangle is 80 feet. Find the dimensions if the length is 5 feet longer than 4 times the width. Then find the area of the rectangle.

I know that P=2(l+w)

The perimeter of a rectangle is 80 feet. Find the dimensions if the length is 5 feet longer than 4 times the width. Then find the area of the rectangle.

I know that P=2(l+w)

Tutors, please sign in to answer this question.

Middletown, CT

Hi Conny;

L=4W+5

80=2L+2W

80=2(4W+5)+2W

80=8W+10+2W

Let's combine like terms...

80=10W+10

Let's subtract 10 from both sides as we proceed to isolate x...

80-10=10W+10-10

70=10W

Let's divide both sides by 10...

70/10=(10W)/10

7=W

L=4W+5

L=4(7)+5

L=28+5

L=33

Let's check our work...

2W+2L=80

[2(7)]+[2(33)]=80

14+66=80

80=80

Hallandale, FL

l = 4w + 5

P = 2[(4w + 5) + w] = 80

(4w + 5) + w = 80 / 2

5w + 5 = 40

5w = 40 - 5

**w** = 35 / 5 = **7 feet**

**l** = 4 * 7 + 5 = **33 feet**

-------

*Verify the answer: *

*2(33 + 7) = 80 *

*2 * 40 = 80 *

80 = 80

P = 2[(4w + 5) + w] = 80

(4w + 5) + w = 80 / 2

5w + 5 = 40

5w = 40 - 5

-------

80 = 80

- Area 292
- Geometry 1907
- Volume 225
- Length 64
- Math 9888
- Rectangle 58
- Width 41
- Word Problem 5127
- Triangles 199
- Perimeter Word Problem 39