Question

The length of a rectangle is 1 inch less than twice the width. the area is 21 inches^2 what is the length?

Answer 1

Hi.

Formula for area: A = 2l + 2w, where l is the length and w is the width.

Given information:
• l = 2w - 1
• A = 21 in^2

We can plug in our values accordingly and solve for w.

A = 2l + 2w
21 = 2(2w - 1) + 2w
21 = 4w - 2 + 2w
23 = 6w - 2
23 = 6w
3.83 = w

Plug 3.83 for w into 2w - 1 to find length.

2(3.83) - 1
7.66 - 1
6.66

Finally, check your work by plugging your values into the original equation.

21 = 2(6.66) + 2(3.83)
21 = 13.32 + 7.66
21 = 20.98

Answer:
The length is approximately 6.66 inches.