the length of a rectangle is 5cm more than it's width, if the area of the rectangle is 90cm^2 find demensions?

Question

Solve the application problem. Required to show equation used to find solution and properly labeled answers. Completely stuck.

Answer 1

width is x, then length is x + 5

area is length * width

x(x+5) = 90

x^2 + 5x - 90 = 0

use the binomial equation to solve for a real value of x

Answer 2

Let us call the width of the rectangle w. Then the length is 5 more or w+5.

Since the area of a rectangle is given as length x width we get:

w (w+5) = 90, or w^2+5w=90. We can subtract 90 from both sides giving

w^2+5w=90=0. Now you may use the quadratic equation, which is probably the point of this homework assignment.

Answer 3

You're being asked to translate this question into the language of math. Think about what you know.



What's the area? How do you express the area mathematically?



length X width, right?



Now, what else do you know? What do you know about THIS rectangle?



length = width + 5 cm



and



length X width = 90 cm^2



So, take what you know about length, and write out the entire equation, using the values. You need to solve that equation to get the width, then you can figure out the width.



If it helps, draw a rectangle, and label it with what you know.