A school communoty had planned to reduce the number of grade 9 students per class room by constructing additional class room however they constructed 4 less rooms than they planned As the result tye number of students per class was 10 more than they planned if there are 1200 grade 9 students in the school determine the current number of class rooms and the number of students per class

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.