perimeter = sum of all sides
66=4x-2+x+5+3x-1
collecting like terms;
66=4x+x+3x-2+5-1
66=8x+2
66-2=8x
64=8x
dividing both sides by 8;
64/8=8x/8
8=x
substitute x in the given lengths:
4x-2=4(8)-2
4x-2=30
x+5=8+5
x+5=13
3x-1=3(8)-1
3x-1=23
the shortest is x+5=13units