SOLUTION: the length of a rectangle is 7cm more than twice the width. the perimeter is 86cm. find the dimensions of the rectangle. i tried this 86=2(7)+2w 86-14=2w 72/2=2w/2 but

Algebra ->  Linear-equations -> SOLUTION: the length of a rectangle is 7cm more than twice the width. the perimeter is 86cm. find the dimensions of the rectangle. i tried this 86=2(7)+2w 86-14=2w 72/2=2w/2 but       Log On


   

Question 1074080: the length of a rectangle is 7cm more than twice the width. the perimeter is 86cm. find the dimensions of the rectangle.
i tried this
86=2(7)+2w
86-14=2w
72/2=2w/2

but i keep getting the wrong answer
Found 3 solutions by josgarithmetic, ankor@dixie-net.com, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Dimensions 2w+7, and w.

2%282w%2B7%29%2B2w=86

2w%2B7%2Bw=43

3w=43-7
3w=36
highlight%28w=12%29, width

Length is 2w%2B7=highlight%2831%29.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
the length of a rectangle is 7cm more than twice the width.
L = 2w+7
the perimeter is 86cm. find the dimensions of the rectangle
2L + 2W = 86
simplify, divide by 2
L + w = 43
replace L with (2w+7)
(2w+7) + w = 43
3w = 43 - 7
3w = 36
w = 36/3
w = 12 cm is the width
then
L = 2(12) + 7
L = 31 cm is the length
:
:
Check the solution with these dimensions
2(31) + 2(12) =
62 + 24 = 86

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

the length of a rectangle is 7cm more than twice the width. the perimeter is 86cm. find the dimensions of the rectangle.
i tried this
86=2(7)+2w
86-14=2w
72/2=2w/2

but i keep getting the wrong answer 
You're getting the wrong answer because your INITIAL equation is incorrect.

86 = 2(7) + 2w <======= THIS IS WRONG

Let width be W

Then length is: 2W + 7

86 = 2(W) + 2(2W + 7) <========== This is what the equation should be