A small software corporation borrowed $500,000 to expand its software line. The corporation borrowed some of the money at 3%, some at 4%, and some at 5%. Use a system of equations to determine how much was borrowed at 4% when the annual interest was $20,500 and the amount borrowed at 4% was times the amount borrowed at 3%.

One eight-ounce glass of apple juice and one eight-ounce glass of orange juice contain a total of 227 milligrams of vitamin C. Two eight-ounce glasses of apple juice and three eight-ounce glasses of orange juice contain a total of 578 milligrams of vitamin C. How much vitamin C is in an eight-ounce glass of apple juice?

Which is a linear equation?

How many numbers of for which the system of linear equations has no solution?