All formulas have how many variables

All formulas have at least two 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