Question 905658
Let X = the width
the length is 11 less than twice the width so
Length = 2x-11

the perimeter of a rectangle = 2W + 2L so

2X + 2(2X-11) = 86
2X + 4X -22 = 86
add 22 to both sides 
2X + 4X = 108
6X = 108
divide both sides by 6
X = 18

check the answer
2(18) + 2(2(18)-11) = 86
36 + 2(36-11) = 86
36 + 2(25) = 86
36 + 50 = 86
86 = 86