The sum if 2 numbers is 13. Their difference is 3. What are the 2 numbers? Graph these numbers

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

How do i do this activity, is appreciated

The high temp today was 62°. when nighttime comes, the temp will drop 40°. by 4am the temp will drop an additional 40°. what is the temp at 4am?