P = 2(l+w)
substitute for P and l
12+8y = 2 (4x-2y+w)
distribute
12+8y = 8x -4y +2w
solve for w
subtract 8x from each side
12 +8y -8x = -4y+2w
add 4y to each side
12 +12 y -8x = 2w
divide by2
6 +6y-4x =w
the other side is 6+6y-4x
8.8m questions
11.4m answers