Answer:
You use the vertical line test to see if a function is relation is a function
Step-by-step explanation:
A function is a relation with only one output for every input. That means that if the x value and two y values, it is not a function.
I believe it's C) 60 because ideally it would be 3 for every 25, 20 x 25 = 200, so then you would do 3 x 20 = 60
25(1)=25
25+0=25
Those are the only ones that are true