If I have a multiple regression model in which there are more than 1 or 2 terms that are non-linear with the dependent variable Y, then what can I do to transform these variables? Can I have more than 1 squared term in a regression model?

Textbook examples usually show:
Y=a+bX+ BX2

What if I have both age and education that need to be transformed in one single equation? Can I do that? Or, I have to use other methods to estimate the model?

Charles