How many different variables are in the expression 5g2−2h+9%0D%0A5%0D%0A%0D%0A2%0D%0A−%0D%0A2%0D%0Aℎ%0D%0A+%0D%0A9%0D%0A?

There are three different variables in the expression: g, h, and ℎ.