2000 tickets were sold in an exhibition on Saturday. The cost of an adult ticket is $4 and a child’s ticket is $2. The total amount of revenue collected was $6400. Find the number of adult tickets and the number of child tickets sold.

Answer:1,200 tickets sold at $4.00 each; and 800 tickets sold at $2.00 each, final and correct answer.Step-by-step explanation:Let x = # of adult tickets sold (at $4.00 each)Let y = # of child tickets sold (at $2.00 each)We can take the above information, along with the 2000 tickets sold and the $6,400 collected, to get the following two math statements:x + y = 2000    (Total unknown number of $4.00 + total unknown number of $2.00 tickets, equals a total of 2,000 tickets sold4x + 2y = 6400  ($4.00 * unknown number of $4.00 tickets + $2.00 * unknown number of $2.00 tickets, equals the total of $6,400 collected in ticket salesSo, write these as:x + y = 20004x + 2y = 6400Take the first equation:  Turn it into a y= statement, by subtracting 'x' from both sides, to get:y = 2000 - xNext, go to the 2nd equation.  Where you see the 'y', substitute the y-value in its place:  '2000 - x'This gives you:4x + 2 (2000 - x) = 6400This then gives us:  4x + 4000 -2x = 6400Collect like terms to get:2x + 4000 = 6400Subtract 4000 from both sides to get:2x = 2400Next, divide both sides by 2, to get x = 1200We now know that there were 1,200 adult ($4.00) tickets sold; put this information back into the original equation:1200 + y = 2000Next, subtract 1200 from both sides, so that we can solve for y; which is:y = 800Next, check our work, by substituting back into the two original equations:1200 + 800 = 2000    [Check]4 * 1200 + 2 * 800 = 4800 + 1600 + 6400    [Check]So:  1,200 tickets sold at $4.00 each; and 800 tickets sold at $2.00 each, final and correct answer.please mark as brainliest