How are real numbers different than integers?

What term makes it inconsistent y=2x - 4

Olga bought a new skirt that cost $20. sales tax is 5%. how much did olga pay, including sales tax? 7.

Delbert keeps track of total of the total number of points he earns on homework assignments, each of which is worth 60 points. at the end of the semester he has 810 points. write an equation for delbert’s average homework score a in terms of the number of assignments n.