Hello!
A variable is a letter that represents an unknown number.
Examples of Variables : x, y, a, z, b, L
Examples of Constants (numbers) : 1, 20, 5.5,
![\pi](https://img.qammunity.org/2019/formulas/mathematics/middle-school/w2mw2141nk3383oncfx010frgx49xcj0c8.png)
Every single character in this equation is a variable, so therefore
A, x, b, y, and c are the variables in this equation.
I hope this helps!