Simplify the expression
2v - 3v =

If you want to simplify this expression you should know that you can add 2v to -3v exact same as adding the 2 to -3 so you will have -1 so your answer to 2v-3v is -1v or -v :)))
i hope this is helpful
have a nice day 

Remember 2v=2 times v=v+v

so this is the same thing as
2 v's minus 3v's aka
v+v-v-v-v=-v
or
2-3=-1
2v-3v=-1v
answer is -v

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