SOLUTION: We were running out of time in my 8th grade Algebra 1 class and my teacher hurried up to try to teach us how to do this problem and I'm completely lost. The question is: find the

Algebra ->  Rectangles -> SOLUTION: We were running out of time in my 8th grade Algebra 1 class and my teacher hurried up to try to teach us how to do this problem and I'm completely lost. The question is: find the      Log On


   



Question 797028: We were running out of time in my 8th grade Algebra 1 class and my teacher hurried up to try to teach us how to do this problem and I'm completely lost.
The question is: find the value of X so the figures have the same perimeter.
The first rectangles length is X+3 and the width is X
The second rectangles length is 14 and the width is X-4
Please help!!!

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
find the value of X so the figures have the same perimeter.
The first rectangles length is X+3 and the width is X
The second rectangles length is 14 and the width is X-4
:
1st rectangle perimeter
P = 2(x+3) + 2x
2nd rectangle perimeter
p = 2(14) + 2(x-4)
P = P, so we have
2(x+3) + 2x = 2(14) + 2(x-4)
2x + 6 + 2x = 28 + 2x - 8
combine like terms
4x + 6 = 2x + 20
4x - 2x = 20 - 6
2x = 14
x = 14/2
x - 7
:
:
I'll let you find the perimeters using x=7, check that they are, indeed, equal