# How do you add variables in math like 6x + 8y?

Do remember when adding variables in expressions, you only can add and subtract variables that are of the same value like $2 \textcolor{red}{x} + 6 \textcolor{red}{x} = 8 \textcolor{red}{x}$ and $7 \textcolor{b l u e}{y} - 8 \textcolor{b l u e}{y} = - \textcolor{b l u e}{y}$
As the variables $x$ and $y$ are different, you cannot add them up in an expression.
Hence an expression like $6 x + 8 y$ cannot be simplified through addition.