David used 40 feet of braid to trim the edges of a quilt that is 12 feet long. how wide is the quilt? use the formula p=2l+2w.
a)3 1/3 feet
b)8 feet
c)14 feet
d) 28 ft
show your work of how u got the answer.

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.