Simplify 12e- 5f-7e+3f

To simplify 12e - 5f - 7e + 3f, we can combine like terms:

12e - 7e - 5f + 3f

Simplifying the coefficients:

(12 - 7)e + (-5 + 3)f

5e - 2f

Therefore, the simplified expression is 5e - 2f.