With this information, we can find a system of inequalities. Remember that "at least" means that the sum of these number is 30 or more, and their difference is 10 or more. So
The solution of this system is attached. Remember that the solution of a system of inequalities is a graphic solutions, the intersection of all three areas is the solution.
However, the problem is just asking for the system that could represent this situation. So, the answer is
1) 475 2)375 You need to multiply 25 by 27 and you get 675 then to get answer one you need to multiply 10 by 20 to get 200 the take 200 away from 675 to get 475 then do the same thing with the second problem 20x15 which is 300 the take 300 away from 675.