There are two factors of -36 such that one factor is 11 less than half of the other factor. choose all the pairs of these factors.

-2 and 18
-6 and 6
3 and -12
4 and -9

-2 and 18both factors of -36...-2 = 18/2 - 11...-2 = 9 - 11-2 = -2
this is one

-6 and 6...both factors of -36-6 = 6/2 - 11-6 = 3 - 11-6 = - 8
this is not one

3 and -12...both factors of -36...3 = -12/2 - 113 = -6 - 11...3 = - 17
this is not one

4 and -9both factors of -36...-9 = 4/2 - 11...-9 = 2 - 11...-9 = -9
this is one

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm