Explain why the equation 2l + 2w = 4(l - w + 7) is true for the rectangle

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. 9/9/2013 | Parviz F.

 you can find the perimeter of rectangle if you subtract the width from the length, add 7 inches, and multiply the result by 4. b.Explain the equation 2L +2w=4(L-w+7)

With a continuous thought process.