math

classic Classic list List threaded Threaded
2 messages Options
john.k john.k
Reply | Threaded
Open this post in threaded view
|

math

Solve for the given length:

The length of a rectangle is 3m longer than its width.

The area of the the rectangle is 154m^2.

what is the width of the rectangle ?
Proof Proof
Reply | Threaded
Open this post in threaded view
|

Re: math

w = width
w + 3 = length   ← length is 3 longer than width

Area of a rectangle = length x width

w(w + 3) = 154   ← substituted into area formula
w² + 3w = 154   ← distributive property
w² + 3w - 154 = 0   ← subtracted 154 from each side
(w + 13)(w - 11) = 0   ← factored into two binomials
w + 13 = 0   or   w - 11 = 0   ← set each factor equal to zero
w = -13   or  w = 11   ← solved each equation for w

w = 11 only  ← width cannot be negative

width = 11m

- Proof