Solve the system of equations. how many 10 oz. boxes were sold

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.

Which function has an inverse that is also a function? a.{(-4,3), (-2, 7), (-1,0), (4, -3), (11, -7)} b.{(-4, 6), (-2, 2), (-1, 6), (4,2), (11, 2)} c.{(-4,5), (-2, 9), (-1,8), (4, 8), (11,4)} d.{(-4,4), (-2, -1), (-1,0), (4, 1), (11, 1)}

The difference between the measures of two complementary angles is 14. find the measure of both angles.