Astore is having a sale on 200 dvd movies. some of the movies are being sold for $10 and some of them are being sold for $12. if the store made $2200 after selling all 200 dvds, how many $12 dvds were sold?

Let x be the number of $12 dvds sold. with this the number off $10 dvds sold is 200 - x. the equation that best represent the given above is,
                        12x + 10(200 - x) = 2200
the value of x is equal to 100. therefore, the number of $12 dvds sold is 100.