Question

Suppose the area of a rectangle is 7.9 in2 and the length is 2.1 in. longer than the width. Find the length and width in inches of the rectangle.

Answer 1

So area=7.9
You know that area is width*height.
You are also given L=W+2.1
So 7.9=W*(W+2.1)
Distribute that to get 7.9=W^2+2.1W
From there you move 7.9 to the other side to get a quadratic, so W^2+2.1W-7.9=0
Use a graphing calculator to solve from there. W=-4.05042, 1.95042
We can eliminate the negative answer as width cannot be negative. So Width=1.95042

Go back to L=W+2.1. Substitute W in, so L=1.95042+2.1
L=4.05042
W=1.95042

Answer 2

This one does not give exact values

Best I could find was that the width = 1.95 and length = 4.05

Answer 3

x(x-2.1) = 7.9
x^2 -2.1 x - 7.9 = 0

solve this using formulas gives 4.05 or -1.95
x must be positive so length = 4.o5 and width = 4.05 - 2.1 = 1.95