25x * 30x = 810

30 people go to an amusement park the total amount of tickets ends up costing 810 dollars.

Student tickets are 25 dollars

Adult tickets are 30 dollars

How many students and adults went?

I would set this up differently Let x = students and y = adults

Now lets set up two simultaneous equations:

One for the money

25 x + 30 y = $810

and another for the number of people x+y=30

Now let's get y in terms of x If x+y=30 then y=30-x (I subtracted x from both sides)

Now I am going to substitue 30-x for y in the first equation:

25x + 30 (30 - x) = 810

25x + 900 - 30x = 810

Combine like terms (25x - 30x = - 5x)

-5x + 900 = 810

Subtract 900 from both sides

-5x = - 90 (810 - 900 = - 90)

And finally divide both sides by - 5

x = 18 So 18 students went.

Now back to our 2nd equation

x+y=30 substitute 18 for x 18 + y = 30 subtract 18 from both sides

y = 12 adults

18 students and 12 adults (30 people)

Let's check

18 x $25 + 12 x $30 = $810

$450 + $360 = $810

It works!