Hi there! The domain of a function refers to the values that can be validly input for x. In laymen's terms, domain is the x-values that exist on a graph of the equation. 
If we were to plug in y=-2x+5 into a calculator that shows an infinite graph, we would see that the line of the equation would extend both ways infinitely! This means that all real numbers can be inputs for x, because for every x value that exists there is a corresponding y value. 
This means that D. All real numbers, is your answer.
Hope it helps! :)
        
             
        
        
        
By Hand
Step 1: 
Put the numbers in order.
1, 2, 5, 6, 7, 9, 12, 15, 18, 19, 27.
Step 2: 
Find the median.
1, 2, 5, 6, 7, 9, 12, 15, 18, 19, 27.
Step 3: 
Place parentheses around the numbers above and below the median. 
Not necessary statistically, but it makes Q1 and Q3 easier to spot.
(1, 2, 5, 6, 7), 9, (12, 15, 18, 19, 27).
Step 4: 
Find Q1 and Q3
Think of Q1 as a median in the lower half of the data and think of Q3 as a median for the upper half of data.
(1, 2, 5, 6, 7),  9, ( 12, 15, 18, 19, 27). Q1 = 5 and Q3 = 18.
Step 5: 
Subtract Q1 from Q3 to find the interquartile range.
18 – 5 = 13.
        
                    
             
        
        
        
Answer:

Step-by-step explanation:
Given the equation;

Rearranging the equation, we have;

Lowest common multiple (LCM) of S and T is ST.

Cross-multiplying, we have;

Making R, the subject of formula;
