Algebra Need Help Pls. Can someone explain to me how to do this?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.

Which description is represented by a discrete graph? kiley bought a platter for $19 and several matching bowls that were $8 each. what is the total cost before tax? the temperature at 9 a.m. was 83° f and is heating up at an average rate of 6°f per hour. what is the temperature x hours later? juan ate an egg with 78 calories and some cereal with 110 calories per serving for breakfast. what is the total amount of calories he consumed? a bottle contained 2,000 ml of liquid and is being poured out at an average rate of 300 ml per second. how much liquid is left in the bottle after x seconds?