SOLUTION: A rectangle has a perimeter of 140cm. The length of the rectangle is three times the width. Find the difference between the length and the width.

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Question 877404: A rectangle has a perimeter of 140cm. The length of the rectangle is three times the width. Find the difference between the length and the width.
Found 2 solutions by dkppathak, josgarithmetic:
Answer by dkppathak(439) About Me  (Show Source):
You can put this solution on YOUR website!
A rectangle has a perimeter of 140cm. The length of the rectangle is three times the width. Find the difference between the length and the width.
perimeter of rectangle =2(l+b) =140
(l+b) = 70
as per given condition l=3b by substituting
3b +b =70
4b =70
b=70/4
b= 17.5
L= 3x17.5 =52.5
l-b= 35 answer

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
w and L.
2w+2L=140 simplifies to w+L=70.
L=3w. Length L is larger than width.

Question asks, what is L-w?
Try looking at w+L=70 and L=3w to make substitutions for L-w.
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w=70-L.
L-w=L-(70-L)=L-70+L=2L-70, but the question's answer should be a VALUE.

Solve for L and w, and then finding their difference will or can be a value.
Take the system: 3w-L=0 and w+L=70. Add left members and right members will eliminate L to show 4w=70;
w=2%2A35%2F%282%2A2%29
w=35%2F2.
L=3w as found at the beginning of the question.
L=3%2835%2F2%29
L=105%2F2
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highlight%28w=35%2F2%29 and highlight%28L=105%2F2%29.
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The question, what is highlight_green%28L-w%29?
105%2F2-35%2F2=70%2F2=highlight%2835%29.