9514 1404 393
Answer:
375 hamburgers
Step-by-step explanation:
Let h represent the number of hamburgers. Then h+63 is the number of cheeseburgers, and the combined total is ...
h +(h +63) = 813
2h = 813 -63 = 750
h = 750/2 = 375
375 hamburgers were sold on Saturday.
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<em>Additional comment</em>
In a "sum and difference" problem like this, the smaller number is half the difference between the sum and the difference. h = (813 -63)/2 = 375. This generic solution applies to all "sum and difference" problems.
1. 13*13*13 =2197
2. 2/5*2/5 = 4/25
3. 0.9*0.9 = 0.81
The answer is 38.8 repeating. Might as well just round it
1/5 is an expression that represents 1÷5= .2
Since the return decimal equivalent doesn't go on forever and has a finite end, this is a member of the rational number set.
I would compute sqrt(1 + 160pi^2) first to get approximately 39.75093337
Add this to 1 and we have 40.75093337
Then divide over 2pi to get a final approximate result of 6.48571248
So x = 6.48571248 is one approximate solution
In short, I computed 
only focusing on the plus for now.
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If you were to compute 
you should get roughly -6.167402596 as your other solution. Each solution can then be plugged into the original equation to check if you get 0 or not. You likely won't land exactly on 0 but you'll get close enough.
