How is the domain of a rational graph determined for f(x)=2x+6/x-1

Given a normal distribution with µ =50 and σ =4, what is the probability that 5% of the values are less than what x values? between what two x values (symmetrically distributed around the mean) are 95 % of the values? instructions: show all your work as to how you have reached your answer. don’t simply state the results. show graphs where necessary.