Final answer:
By setting up a system of equations based on the cost of the ads and the total budget, we solve for x and y, which represent half-page and full-page advertisements respectively. Gavin buys 7 half-page advertisements and 5 full-page advertisements.
Step-by-step explanation:
To solve this problem, we need to set up a system of equations based on the given information. Let's define x as the number of half-page advertisements and y as the number of full-page advertisements that Gavin wants to purchase. Since each half-page ad costs $50 and each full-page ad costs $80, and Gavin has a budget of $750 for 12 ads, we can write the following equations:
- 50x + 80y = 750 (Budget constraint)
- x + y = 12 (Number of advertisements)
To find the number of half-page and full-page ads, we can solve this system of equations simultaneously. Multiply the second equation by 50 to help with elimination:
- 50x + 80y = 750
- 50x + 50y = 600
Subtract the second equation from the first:
Dividing both sides by 30 gives us:
We substitute y = 5 into x + y = 12 to find the value of x:
Gavin purchases 7 half-page advertisements and 5 full-page advertisements.