How do u write function notation and what variable does function notation replace

How do i do this activity, is appreciated

Acircus act has 3 times as many elephants as acrobats. jorge noticed that all together there were 56 legs in the circus ring. how many elephants were in the show?

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample