The equation 10 x + 12 = $72.00 shows the total cost for x people attending a concert. how many people attended the concert?

First, you have to get rid of all of the non-variable numbers except one of them.

Subtract.

 72
-12
60

Now, you have 10x=$60.00
Divide both sides by 10.

60÷10=6
So, the final answer you get is x=6
This means that 6 people attended the concert (that's a pretty lonely concert if you ask me).

The answer would be 7 cages