Answer:
c
Step-by-step explanation:

Let the capacity of bus be x students
And van be y students, now ;
From the given statements we get two equations ~


multiply the equation (2) with 2 [ it won't change the values ]


Now, deduct equation (1) from equation (3)




Therefore each bus can carry (x) = 45 students
Now, plug the value of x in equation (1) to find y ~







Hence, each van can carry (y) = 17 students in total.
X^2-9=-5
x^2-4=0
(x+2)(x-2)=0 [Difference of Two Squares]
x=-2,2
-2 is the smaller root.
Isolating the x^2 is the simplest way. it would only be three steps.