SOLUTION: please guide me on how to solve this problem: the length of a rectangle is 5cm. more than twice the width. the perimeter of the rectangle is 34 cm. find the dimensions of the rec

Algebra ->  Rectangles -> SOLUTION: please guide me on how to solve this problem: the length of a rectangle is 5cm. more than twice the width. the perimeter of the rectangle is 34 cm. find the dimensions of the rec      Log On


   

Question 249465: please guide me on how to solve this problem:
the length of a rectangle is 5cm. more than twice the width. the perimeter of the rectangle is 34 cm. find the dimensions of the rectangle.
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
Turn each statement into an equation using the fewest possible unknowns.
.
L = length of the rectangle
.
Length is twice the width plus 5.
L = 2W + 5
.
P = perimeter of a rectangle.
P = 2L + 2W = 2(L + W)
P = 34 (given)
.
Substituting what we know...
34 = 2(L + W)
.
Divide both sides by 2...
17 = L + W
.
Substituting L = 2W+5...
17 = 2W + 5 + W
.
Collecting terms and subtracting 5 from both sides
12 = 3W
so
3W = 12
.
Dividing both sides by 3
W = 4
.
L = 2W+5
L = 2(4)+5
L = 8+5
L = 13
.
Checking the perimeter
P = 2(L+W) = 2(13+4) = 2(17) = 34
.
Checks.