Answer:
500 student tickets; 1500 non-student tickets
Explanation:
Write out the problem as equations.
10s+20n=35,000
s+n=2,000
Where s is the number of student tickets sold and n is the number of non-student tickets sold.
Then, solve for one variable. Either works. I'm going to solve for s first.
Take the second equation and re-write it so that n is alone on one side of the equation.
n=-s+2,000
Then plug (-s+2,000) into the first equation for n.
10s+20(-s+2,000)=35,000
Then solve.
10s-20s+40,000=35,000
-10s=-5000
10s=5000
s=500
So 500 student tickets were sold. That means that 1500 non-student tickets were sold.