Answer:
The simpler way is:
SP = 0.85*RP
Step-by-step explanation:
Suppose that we have a given amount A. and now we take a given percentage, X%, off.
The new amount will be:
New amount = A - (X%/100%)*A = A*(1 - X%/100%)
This is the general formula.
In this case, we know that the store has advertised 15% off, then we have X% = 15%
Then if:
SP = sales price
RP = regular price
We will have the equation:
SP = RP - (15%/100%)*RP = RP - 0.15*RP
This is what Jill found, but if we use the general equation above, we will find that:
SP = RP*(1 - 15%/100%) = RP*(1 - 0.15) = RP*0.85
So we just need to multiply the regular price by 0.85 to get the sales price.
