SOLUTION: The length of a rectangle is 1 foot less than three times the width. The area of the rectangle is 80 square feet. Find the length and width of the rectangle. Use the quadratic equa

Question 818632: The length of a rectangle is 1 foot less than three times the width. The area of the rectangle is 80 square feet. Find the length and width of the rectangle. Use the quadratic equation to solve.
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
L = 3w - 1
Lw = 80
---
Lw = 80
(3w - 1)w = 80
3ww - w - 80 = 0
3w^@ - w - 80 = 0
---
the above quadratic equation is in standard form, with a=3, b=-1, and c=-80
---
to solve the quadratic equation, by using the quadratic formula, plug this:
3 -1 -80
into this: https://sooeet.com/math/quadratic-equation-solver.php
---
the two real roots (i.e. the two solutions), of the quadratic are:
w = 5.33333333 = 5+1/3 = 16/3
w = -5
---
the negative root doesn't make sense for width, so use the positive root:
---
answer:
w = 5.333 ft
L = 15 ft
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Convert fractions, decimals, and percents:
https://sooeet.com/math/fraction-decimal-percent.php
---
Calculate and graph the linear regression of any data set:
https://sooeet.com/math/linear-regression.php
RELATED QUESTIONS
The length of a rectangle is one foot less then three times the width. Find the length... (answered by chriswen)

the area of a rectangle is 80 square feet and its length is 1 foot more than 3 times its... (answered by checkley71)

the length of a rectangle is 2 feet less than three times the width. the area of the... (answered by Cromlix)

The length of a rectangle is 7 foot less than 2 times the width. Find the dimensions of... (answered by unlockmath)

the perimeter of a rectangle is 52 feet. the length is 2 feet shorter than three times... (answered by Seutip)

The width of a rectangle is 16 feet less than 3 times the length . if the area is 35... (answered by Fombitz)

The width of a rectangle is 12 feet less than the length. The area of the rectangle is... (answered by Fombitz)

The width of a rectangle is 1 foot less than the length. The area is 2 feet squared. Find (answered by solver91311,richwmiller)

The length of a rectangle is 6 feet less than 3 times its width. The area is 360 square... (answered by mananth)