a revenue of $1500 is obtained from the sales of item A at $50 each and item B at $25 each. Write an equation that shows the relationship between the numbers of items sold.
Let the amount of sales of item A be 'a', and the amount of sales of item B be 'b'.
then since a sales for 50$, you get 50a. since b sells for 25$, you get 25b.
Therefore, since the total revenue is $1500, you have for the final equation:
50a + 25b = 1500
+214 
