Astore sells pencils in small and large boxes. a large box has ten times as many pencils as a small box. mr. adachi buys 5 small boxes and 2 large boxes, for a total of 250 pencils. mr. adachi sets up a system of equations to model this situation. one of the equations is y = 10x. what is the other equation? enter your answer in ax + by = c form, where a and b are whole numbers with no common factor other than 1.