PLS HELP ME

What are the soultion(s) to the quadratic equation 40- x^2=0

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?