Question 1094030
<br>You got a perfectly good formal algebraic solution to your problem....<br>
If you just need to get the answer quickly by any method, try a little logical analysis.<br>
There were a total of 650 burgers sold, with 50 more hamburgers than cheeseburgers.  So "take away" those "extra" 50 hamburgers; that leaves equal numbers of hamburgers and cheeseburgers, with a total of 600.
But that means 300 of each.
Now add back in the "extra" hamburgers to find the final answer of 350 hamburgers.