A rectangle's width is x and its length is 2x-1. Its area is 21. Find its dimensions.
my work so far:
21 = x(2x +1)
21 = 2x^2 + x
I was wondering how I would continue to solces this problem.
You missed a sign:
correct that sign (21=2x^2-x)
factor:
2x^2=x-21=0
(2x-7)(x+3)=0
x=7/2 is only positive solution
width=3.5
length=6