Range and domain of f(x)=2/7x-2

Let l = length of larger piece  smaller piece = 5 greater than 1/4 l = 1/4 l + 5  also, the smaller piece = 12  so, put them together:   1/4 l + 5 = 12  and solve for l.  subtract 5 from both sides:   1/4 l = 7  multiply both sides by 4:   l = 28  the length of the bigger piece is 28 meters, and  the total length of the carpet is 28+12 = 40 meters.