The expression would be m - 4 because if Marty ran 4 more miles than Shana, that means that Shana ran 4 less miles than Marty.
The four inequalities are less than, less than or equal to, greater than, and greater than or equal to. Less than means that a number is less than the other number. For example, if you say 4 is less than 7 it is because 4 is less than 7 by 3 which makes 7 value more than 4. For less than or equal to, it means that the number or variable is less than or the same number as the other number. For example, if you say x is less than or equal to 9, that means that x is less than 9 or equal to 9. For greater than, it means that the variable is greater than the other number. For example, if x if greater than 10 than the variable has to be greater than 10 or 11 and so on. For greater than or equal to, it means that the variable is greater than the other number or equal to that number. For example, if x is greater than or equal to 12, then x is greater than 12 or 13 and up or x is equal to 12 or x is 12.
