Question 1151840
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Let y = the number of advertisements that resulted in a sale of the property.


Then 49-y is the number of advertising that did not result in a sale of the property.


Your equation to find y is this revenue equation


    140*y - 30*(49-y) = 3120.


From the equation,


    y = {{{(3120 + 30*49)/(140+30)}}} = 27.    <U>ANSWER</U>
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