Question 91007
Since you don't know how many of the items a and b were sold to produce the revenue of $1,500, you can assign a variable to represent each quantity of a and b.
Let x = the number of item a sold at $50 each.
Let y = the number of item b sold at $25 each.
The total of the individual sales produced $1,500 in revenue.
You can write an equation showing this relationship as follows:
x($50) + y($25) = $1,500
In words, this would read:
The number of items a (that's x) times the price of each item (that's $50) plus the number of items b (that's y) times the cost of each item (that's $25) equals the total revenue of $1,500.