All formulas have how many variables

All formulas will have more than one variable. You need at least one independent variable and one dependent variable, so a minimum of 2.

For example, the formula for the diameter given the radius is:

d = 2r

The formula for area of a square is:

A = s²

The formula for the area of a circle is:

A = πr²

And you can have more, like the volume of a box is:

V = lwh

Or the amount of money you have with periodic compounding is:

A = P (1 + r/n) ^ (nt)

Answer:

More than 1

All formulas have at least two variables.