SOLUTION: Please Help! The length of a rectangle is 3 more than the width. If the length is doubled and 4 is added to the width, a new rectanlge is formed with an area of 104 square units

Algebra ->  Square-cubic-other-roots -> SOLUTION: Please Help! The length of a rectangle is 3 more than the width. If the length is doubled and 4 is added to the width, a new rectanlge is formed with an area of 104 square units       Log On


   

Question 39429: Please Help!
The length of a rectangle is 3 more than the width. If the length is doubled and 4 is added to the width, a new rectanlge is formed with an area of 104 square units larger than the area of the original rectangle. find the dimensions of the original rectangle.
Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
Length of a rectangle = x+3
Width = x
Area = %28x%2B3%29%28x%29=x%5E2%2B3x
Length doubled = 2(x+3) -->2x+6
4 added to the width = x+4
Forms 104 larger area = x%5E2%2B3x%2B104
Equation:
%282x%2B6%29%28x%2B4%29=x%5E2%2B3x%2B104
2x%5E2%2B14x%2B24=x%5E2%2B3x%2B104
x%5E2%2B11x-80=0
x+=+%28-11+%2B-+sqrt%28+11%5E2-4%2A1%2A-80+%29%29%2F%282%2A1%29+
Simplfy and remove the negative
x=5
5+3=8
Hence, the width is 5cm and the length is 8cm.
Paul.