When dividing the expression \( 4x + 2y - 8 \) by \( 2b \), we need to look at the variables present in both the numerator and denominator.
The numerator \( 4x + 2y - 8 \) contains two variables, \( x \) and \( y \). The denominator \( 2b \) contains one variable, \( b \).
When performing the division, the resulting quotient will still involve all variables from the numerator and denominator. Therefore, the total number of different variables present in the quotient will be:
- \( x \) from the numerator
- \( y \) from the numerator
- \( b \) from the denominator
This amounts to 3 different variables (\( x \), \( y \), and \( b \)).
Thus, the answer is:
3