Step-by-step explanation: You can test whether a graph is a function by checking to see if the same X value is used twice. You can also use the Vertical line test to check aswell. Research Vertical Line Test if you are clueless. But Yes, this is a function
If you do 460/20 you get the gas mileage. The gas mileage is 23. If you do 23*70 you get 1610 miles out of 70 gallons of gas. (Double-check to make sure I'm correct)
