Question 1023777: A sign says that the price marked on all music equipment is 30%off the original price ,you buy an electric guitar for the sale price of $315 , what was the original price?
How to solve this or what formula should I use
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! the basic formulas involved are:
sale price = original price minus discount.
discount = original price * discount percent / 100.
let s represent the sale price.
let p represent the original price.
let d represent the discount.
let k represent the discount percent.
the above formulas become:
s = p - d
d = p * k/100
we know that s = 315.
we know that k = 30.
formulas become:
315 = p - d
d = p * 30/100
simplify these formulas to get:
315 = p - d
d = .3p
since d = .3p, then the first formula can be shown as:
315 = p - .3p, after we replace d with its equivalent value of .3p.
simplify to get 315 = .7p.
divide both sides of this equation by .7 to get:
315/.7 = p
solve for p to get p = 450.
the original price is 450.
30% of 450 = 135.
450 - 135 = 315, which is the sale price.
numbers look good.
solution is that the original price is 450.
it doesn't really matter what variable names you choose as long as you can keep track as to what variable name represents what.
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