So you mean that . If this is true then it does not make sense. How would you subtract a number from a vector?
The position vectors a, b, c of points A, B, C satisfy c = (3b-1)/(3-1). What is the ratio AC:CB? and where would C be located on a line with A and B (between A and B, next to B or next to C)?
Not sure how to do this - help would be appreciated