Dimensions of a rectangle

Question

The area of a rectangle is 250 the length is five feet longer than twice the width, what are its dimensions

Answer 1

L=5+2w

A = 250 = Lw = (5+2w)w = 5w + 2w^2

5w + 2w^2 = 250

2w^2 +5w -250 = 0

use the quadratic formula: x=-b/2a +/- (1/2a)sqr(b^2-4ac) with a=2, b=5, c= -250

w = -5/4 +/- (1/4)sqr(25+2000)

ignore the negative square root

w = (sqr2025 -5)/4 = (45-5)/4 = 40/4 = 10 feet wide

L = 5+2w =5+2(10) = 25 feet Long

check the anwers

A= Lw = 25(10) = 250 ft^2

dimensions are 10 feet by 25 feet