SOLUTION: Solving a word problem using a quadratic equation with rational roots The length of a rectangle is 5 m more than twice its width, and the area of the rectangle is 42 m^2. Find t

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Question 360493: Solving a word problem using a quadratic equation with rational roots
The length of a rectangle is 5 m more than twice its width, and the area of the rectangle is 42 m^2. Find the dimensions of the rectangle.
Length: ? m
Width: ? m
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

let x represent the width, length then is (2x+5)

x(2x+5) = 42m^2

2x^2 + 5x - 42m^2 = 0

(2x - 7)(x + 6) = 0

x + 6 = 0

x = -6 cannot use

2x - 7 = 0

x = 7/2m 

width is 7/2m and the length is (7 + 5) = 12m

checking our answer

7/2m * 12m = 42m^2