It’s about solving systems of equations does anyone know the answer please

Brent paid for 6 avocados with a $20.00 bill. he received $10.40 in change. construct and solve an equation can be used to find the price , of each avocados

Assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.

Keith runs 5 miles in 38 minutes. at the same rate, how many miles would he run in 57 minutes