m(5i+Vj)+m(2i−Vj)=(m+m)(3i−2j)(5m+2m−3m−3m)i+(mV−mV+2m+2m)j=0i+0j
Consider the i component. The i component on the left hand side must be the same as the i component on the right hand side, that is zero.
5m+2m−3m−3m=02−=0=2
