Antonio thinks of a number.
He then does the following operations:
Multiply by 2, subtract 3, multiply by 3 then add 23 (in that order).
He finds that the number he ends up with is 8 times his original number.
What was Antonio's original number?
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This question is best answered by forming an algebraic equation then solving it. Let Antonio's original number be x.
First operation gives 2x
Second operation gives 2x 3
Third operation gives 3(2x 3)
Fourth operation gives 3(2x 3) + 23
This is equal to 8 times the original number
3(2x  3) + 23 = 8x
6x 9 + 23 = 8x
...
x = 7
Antonio's original number was 7.
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