Can someone help I got wrong at this question

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.

Which of the following is equal to the rational expression when x is not equal to -2 or -6?

Stefania pours 2 liters of orange juice and 1.5 liters of pineapple juice into a punch bowl. how many liters are in the punch bowl?