We have a problem in AP Physics that we just can't get. It has to do with vector addition. The problem is:

If aA+bB+C=0, find the magnitudes of a and b.

*A, B, and C are vectors*
*i and j are unite vectors*
A=(6.0i-8.0j)units
B=(-8.0i+3.0j)units
C=(26.0i-19.0j)units

How is that possible without a second equation for the relationship between a and b? You can't do substitution or anything. And by lokking at it for an extended period of time, we found that a=5 and b=7 works, but we don't know how to find that using algebra.

help??

You have a second equation. Do the i, j separately..

i:
6a -8b+26=0
j
-a8+3b-19=0

solve for a,b