👉 Subbing, in algebra and other mathematical contexts, is a process of substituting one quantity for another. This can be done by performing an operation on each variable (or unknown) that is present in both quantities being substituted. For example, if you are given two expressions: 1. \( x + 2 \) 2. \( y - 3 \) To substitute the expression \( y - 3 \) for \( x + 2 \), you would perform the operation of substitution