The length of a rectangle is 4cm more than the width the area is 96cm

^{2 }The length of a rectangle is 4cm more than the width the area is 96cm^{2 }

Tutors, please sign in to answer this question.

Cambria Heights, NY

In this problem we have the length (l) and the area (A) of a triangle. The length is 4 more than the width. we can have the width be represented by w. Therefore, if the length of the triangle is 4 more than the width, the length would be:
**w + 4**.

The equation for finding the area of a rectangle is: **A = lw**

If if I fill out the equation with our filler values, we get: 96cm^{2} = (w+4)(w). Then you solve -

96cm^{2} = (w+4)(w)

96 = w^{2 }+ 4w

0 = w^{2} + 4w - 96

Oh hey, quadratic equation! First we need to separate it into two parts.

0 = (w + )(w - ) Cool. Now we need two numbers whose product = 96, and whose difference = 4.

0 = (w + 12)(w - 8) Awesome. Now set each side equal to 0 and solve. Why? Because anything times 0 equals 0. Therefore, the equation will be true as long as one of those two parts is equal to 0.

w + 12 = 0

w = -12

w - 8 = 0

w = 8

w = -12 ; w = 8. Only one of these answers is possible for a measurements. You can't have negative length measurements because then you're traveling into other dimensions. And if you are, please take picture, that is groundbreaking science.

So there's the width! w = 8. So what's the length again? Oh right 4 more than the width.

l = 12 and w = 8.

John E.

Physics and Math tutor - Masters from Cornell and Columbia University

New York, NY

4.8
(124 ratings)

Sergey O.

Computer Science/Programming Tutor, Math Ph.D.

New York, NY

4.9
(51 ratings)

Sean B.

Talented Math and SAT tutor for all

New York, NY

5.0
(18 ratings)

- Math Help 3960
- Math 6723
- Math Word Problem 2787
- Math Problem 718
- Math Question 619
- Math Help For College 1152
- Mathematics 362
- Math Answers 312
- Algebra Help 868
- Algebra 1 3023

Find a tutor fast. Get the app.

Are you a tutor? Get the app for tutors

© 2005 - 2016 WyzAnt, Inc. - All Rights Reserved