
Elizabeth A. answered 11/15/19
Patient and Energetic Ivy League Math and Chemistry Tutor
Here you have to solve for two different variables using two equations.
v = number of students per van
b = number of students per bus
South-West High School filled 1 van and 6 buses with 324 students:
v + 6b = 324
North-West High School filled 9 vans and 3 buses with 264 students
9v + 3b = 264
Use substitution to solve for one variable. The easiest equation to use is South-West. Isolate v first:
v + 6b = 324
v = -6b + 324
Plug this into North-West equation to solve for b:
9(-6b + 324) +3b = 264
-54b + 2916 + 3b = 264
-51b + 2916 = 264
-51b = -2652
b = 52 students
Then plug this into either equation - South-West is easier.
v + 6(52) = 324
v + 312 = 324
v = 12 students
You can check both equations with these numbers to make sure they are correct.