SOLUTION: I would appreciate some help on this question please! During a sale, the price of a shirt was decreased by 30%. By what percent must the sales price be increased to restore it

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Question 719977: I would appreciate some help on this question please!
During a sale, the price of a shirt was decreased by 30%. By what percent must the sales price be increased to restore it to its original price?
Thank you!
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +p+ = the original price
With discount:
price = +p+-+.3p+
+p+-+.3p+=+.7p+
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Let +x+ = the fraction that the discounted price must be
increased by to equal the original price
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+.7p+%2B+x%2A%28+.7p+%29+=+p+
Divide both sides by +p+
+.7+%2B+.7x=+1+
+.7x+=+.3+
+x+=+3%2F7+
+x+=++.4286+
The discounted price is increased by .4286
or 42.86% to equal the original price
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check Suppose the original price was $70
+70+-+.3%2A70+=+70+-+21+
+70+-+21+=+49+
and
+49+%2B+.4286%2A49+=+49+%2B+21.0014+
+49+%2B+21.0014+=+70.0014+
close enough