SOLUTION: The area of a rectangle is 105 cm squared. If the length is (x) and the width is (2x+1), find the width.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The area of a rectangle is 105 cm squared. If the length is (x) and the width is (2x+1), find the width.      Log On


   

Question 1008764: The area of a rectangle is 105 cm squared. If the length is (x) and the width is (2x+1), find the width.
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
The area of a rectangle is:
A=105cm%5E2
If the length is x and the width is %282x%2B1%29, then
x%282x%2B1%29=105
2x%5E2%2Bx=105
2x%5E2%2Bx-105=0
2x%5E2%2B15x-14x-105=0
%282x%5E2-14x%29%2B%2815x-105%29=0
%282x%5E2-14x%29%2B%2815x-105%29=0
2x%28x-7%29%2B15%28x-7%29=0
%28x-7%29%282x%2B15%29+=+0
solutions: we need only positive solution since we are looking for width
if %28x-7%29+=+0=>highlight%28x=7%29-> the length
and %282x%2B1%29=2%2A7%2B1=>highlight%28%282x%2B1%29=15%29->the width