The correct answers are the first and fourth options
Here, we want to select all stories that goes in line with the equation
a) This can be represented
By multiplying x which is the cost of one training hour by the number of hours which is 40;and subtracting the one-time discount, we can get the or equate to the total paid
b) This cannot be represented
In this case, 20 multiplied by x would give the total amount to be paid after which we can deduct the discount
c) This cannot be represented
It multiplies the charge x by the 20 training hours would give 20x; less the discount of $40 would give 620
d) This can be represented
This narrative is similar to what we have at the first option since the total cost would be 40x and less the discount of $20 would give the after discount payment amount