Charles thinks of a number.
He then does the following operations:
Multiply by 2, subtract 2, multiply by 3 then add 18 (in that order).
He finds that the number he ends up with is 8 times his original number.
What was Charles's original number?
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This question is best answered by forming an algebraic equation then solving it. Let Charles's original number be x.
First operation gives 2x
Second operation gives 2x- 2
Third operation gives 3(2x- 2)
Fourth operation gives 3(2x- 2) + 18
This is equal to 8 times the original number
3(2x - 2) + 18 = 8x
6x- 6 + 18 = 8x
x = 6
Charles's original number was 6.
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