What number is equivalent to the fraction 18 over 5

How do you use the additive inverse to evaluate an expression that uses subtraction in a full sentence

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236

What is the interquartile range (iqr) of the data set represented by this box plot?