Part B:

The high temperature this Sunday is expected to be 5 degrees warmer than the high temperature this Saturday.

Using the line c = 2t - 89, how many more cups of lemonade should Lin expect to sell on Sunday than

Lin should expect to sell 10 cups more

Step-by-step explanation:

The line c = 2t - 89 relates the cups Lin expect to sale (c) with the high temperature of the day (t)

If high temperature on Saturday is t1, then high temperature on Sunday is (t1+5)

Cups sold on Saturday are: 2t1 - 89

Cups sold on Sunday are: 2 (t1+5) - 89 = 2t1 + 10 - 89

Cups sold on Sunday - Cups sold on Saturday:

2t1 + 10 - 89 - (2t1 - 89) = 2t1 + 10 - 89 - 2t1 + 89 = 10