Find the measure with the “?” I’m so confused I have no idea how to solve this PLEASE HELP

This stem-and-leaf plot represents the heights of the students on ralph's basketball team. one student's height is missing from the plot. if the mean height of all the students on the team is 61 inches, what is the missing height? a. 55 in. b. 59 in. c. 61 in. d. 65 in.

Which inequality is equivalent to -3x < -12? x < 4 , x < -4 , x > 4, x > -4

Solve this 364x-64x=300x and 12(x2–x–1)+13(x2–x–1)=25(x2–x–1)