SOLUTION: how do I solve a number is decreased by 30% and then doubled to be 91. What was the original number?

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Question 997308: how do I solve a number is decreased by 30% and then doubled to be 91. What was the original number?
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
x= the original number
When it is decreased by %2230%25%22, what is left is
%22100%25%22-%2230%25%22=%2270%25%22=70%2F100=0.7 of x .
That is 0.7x .
When 0.7x is doubled, the result is
2%2A%280.7x%29 , and that equals 91 .
The equation that state that is
2%2A%280.7x%29=91 .
Solving:
2%2A%280.7x%29=91 can be simplified to 1.4x=91 , because
2%2A%280.7x%29=91<-->%282%2A0.7%29x=91<-->1.4x=91 .
then,
1.4x=91-->x=91%2F1.4-->x=65