For 1200$, a buisness can post an advertisement for 30 days. for 1500$, the advertisement will be posted for 60 days. which function can be used to model the realationship between cost, y, and the number of days, x, that an advertisement will be posted?

You could model this data with the following linear equation: y = 30x + 900

To find this equation, we first need to find the slope. That is the change between the two given amount.

(1500 - 1200) / (60 - 30) = 300 / 30 = 10

Now, we just need to find the y-intercept.

y = 10x + b
1500 = 10(60) + b
1500 = 600 + b
900 = b