For this, I am going to use substitution to find the answer in the system of linear equations.
b=buses
v=vans
11v +50b =294
v+b=9
For the second equation, I am going to multiply it by -11 to eliminate the variable v
11v+50b=294
-11v-11b= -99
Cancel out the variables
39b =195
Divide
195/39b=5b
They took 5 buses
Now that you know b, plug into an equation. I'm going to use the first one
5+v=9
Subtract
9-5=4
They took 4 vans
To check your answers, plug it into the equation you may of not used.
11 (4)+ 50 (5)=294
44+250=294
Tell me if this helps!!!