A restaurant hires an advertising agency to help them attract new customers. The restaurant has an advertising budget that cannot exceed $20,000. The advertising agency advises the restaurant to pay a popular radio station $750 each week to air an ad. If it costs the restaurant $1,000 to produce the ad and w represents the number of weeks the restaurant can pay the radio station to run the ad, fill in the values for a, b, and c to create the inequality that represents the situation. Do not include dollar signs, $, in the response.