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The formula to find the perimeter of a rectangle is: P = 2W + 2L. To solve for " W " in this formula, which steps should be followed?

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Parviz F. | Mathematics professor at Community CollegesMathematics professor at Community Colle...
4.8 4.8 (4 lesson ratings) (4)
P = 2W +2L 
step is keep 2L in one side of equation , and move every thing else to the other side.
In moving any quantity from one side to other, change the sign. ( equivalent of adding or subtracting equal                                                                                                  quantity from both sides of equation).
2L = P - 2W
divide both sides by 2:
 L = p/2 - w
 Step is the same as solving  X in equation of  8 = 2X + 16
 2X = 8 -16 = 8
   X =4 . But, here you solve one variable in terms of other variables. 
Bill N. | Bill-Biology (AP and college), Algebra I/II, precalc, geometry, ASVABBill-Biology (AP and college), Algebra I...
4.9 4.9 (198 lesson ratings) (198)

As you stated the formula of a rectangle is P (perimeter) = 2W (the two widths added together) + 2L (the two lengths added together).

To solve this algebraicly you need to define your variable, or unknown, which in this case is the width or "W".

Now set this same equation with any symbol you wish, "x" is often used, and solve for x.  You could keep W instead of X also if it makes it easier to work the problem.

P= 2x + 2L

isolate the 2x by subtracting 2L from both sides.


Now isolate the x by dividing both sides by 2 and you have


x will be W.  Just put in the numbers of P and L and you will have solved for W.

Tamara J. | Math Tutoring - Algebra and Calculus (all levels)Math Tutoring - Algebra and Calculus (al...
4.9 4.9 (51 lesson ratings) (51)

The perimeter of a rectangle is given by the following formula:     P = 2W + 2L

To solve this formula for W, the goal is to isolate this variable to one side of the equation such that the width of the rectangle (W) can be solved when given its perimeter (P) and length (L).

     P = 2W + 2L

          subtract 2L from both sides of the equation

     P - 2L = 2W + 2L - 2L

     P - 2L = 2W

           divide both sides of the equation by 2

     (P - 2L)/2 = (2W)/2

     (P - 2L)/2 = (2/2)W

     (P - 2L)/2 = (1)W

     (P - 2L)/2 = W

Thus, given that the perimeter (P) of a rectangle is defined by    P = 2W + 2L ,

   then its width (W) is given by    W = (P - 2L)/2