this question is about dimensional analysis involving a number with units and a number with no units, if the question is already answered in another post please redirect me if not here is a simple example, for example, : say i have 2[in]-1. the 1 is dimensionless and the 2 has units of [in]. can I subtract the 2[in]-1=1[in]?or do i leave it as 2[in]-1. this is not from a problem. i was doing dim. analysis on a sol. and ended up with this so i knew i did something wrong, but it got me wondering what to do in a problem that might be stated like this say in a multiple choice. thanks for the time.