Question

The length of a rectangle is 3m longer than the width

the area of the rectangle is 154m^2
what is the width of the rectangle? 10 points

Answer 1

Let x = the width of the rectangle.
Let x+3 = the length of the rectangle.

Since area of a rectangle is A=l*w

154 = x(x + 3)

154 = x^2 + 3x

-154. -154


0 = x^2 + 3x - 154

0 = (x + 14)(x - 11)


Set x + 14 = 0 and x - 11 = 0


Then x = -14 and x = 11

Reject x= -14 since lengths cannot be negative.
Therefore, the width is 11 m and the length is 11+3 or 14 m.

Answer 2

Width: x
Length: x + 3

Area = lw
154 = (x+3)(x)
154= x^2 + 3x
0= x^2 + 3x -154
0= (x+14)(x-11)

Possible solutions: x+14=0 >> x= -14, x-11=0 >> x=11

The answer is x=11 (or in other words the width is 11m) because the width cannot be negative.