You can 
put this solution on YOUR website! .
590 attended a play. Admission $2.00 for adults and $1.00 for kids. $790 of tickets were sold.
How many adult and kids tickets sold
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a = adults 
590-a = kids
Money equation
    2a + 1*(590-a) = 790
From the equation
    a = 
 = 200.
ANSWER.  200 adults and 590-200 = 390 kids.
CHECK.   200*2 + 390*1 = 400 + 390 = 790  dollars total money.   ! Correct !
Solved.