Question

a x + b y = c what are the variables?

Answer 1

Hey!
If A, B, C are representing numbers then they are not the variables. The variables are x and y.
a and b are coefficients and c is a constant.
Hope this helps!

Answer 2

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, $\pi$

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!