Let a=1,-3,2 and b= -1,3,-2 find a-3b

A=<1,-3,2> and b=<-1,3,-2>

a-3b=<1,-3,2>-3<-1,3,-2>
a-3b=<1,-3,2>-<3(-1),3(3),3(-2)>
a-3b=<1,-3,2>-<-3,9,-6>
a-3b=<1-(-3),-3-9,2-(-6)>
a-3b=<1+3,-12,2+6>
a-3b=<4,-12,8>

a-3b=<4,-12,8>

False because how does that work?

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