Can i get some help plzzz

Which function has the smallest y-intercept value

What is the value of m in the equation 1/2 m - 3/4n=16 when n=8

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?