Adult tickets for the school musical sold for $3.50 and student tickets sold for $2.50. three hundred twenty-one tickets for sold all together $937.50. how many of each kind of tickets were sold?

You cannot combine them in only one equation because they represent different things; so you will need two equations.

Now before we construct the two equations; lets set up our variables

Let a represent adult tickets

Let s represent student tickets

Now lets look at what we now about these two when thinking about them in money terms:

$3.50 per adult

$2.50 per student

Total made $937.50

Lets show it algebraically: 3.50a + 2.50s=$937.50

When thinking about the tickets in numbers we now the number sold were 321 so algebraically a + s = 321

Two equations; two variables; we can solve

a + s = 321

which is the same as

s = 321 - a

3.50a + 2.50s = 937.50

Since s = 321-a, we can substitute this into second equation:

3.50a + 2.50 (321-a) = 937.50

3.50a+802.5-2.50a=937.50

3.50a-2.50a+802.5=937.50

1.00a+802.5=937.50

a=135

Then s=321-135

s=186