👉 In math, a subbed variable is a variable that represents a value that has been substituted into another variable. This can be done by replacing the original variable with its value in the second equation or expression. For example, if we have an equation y = 2x + 3 and we want to represent x as y - 1, we would substitute x in the first equation with y - 1 like this: y = 2(x - 1) + 3
