A system of equations is a set of two or more equations sharing the same variables — solving it means finding the values that satisfy every equation at once.
1-A 2-A 3-A 4-B | 5 both 6 10 7 = x = 10, y = 5 8 = x = 5, y = 20 9 = x = 3, y = 2 | 10 = x = 4, y = 2