In an equation with expenses and income, what would be the independent variable?

For the X value as the independent variable, which would it be?

Expenses or income?In an equation with expenses and income, what would be the independent variable?
Income, because your expenses depend on your income.



(assuming you spend your money well of course, haha). It makes sense that if you make like $20,000 a year you'd manage your expenses according. So if you make like $50,000 a year you'd probably have different expenses.In an equation with expenses and income, what would be the independent variable?
it would be income