~~~99 points~~~

jessica purchased a dvd that was on sale for 12% off. the sales tax in her county is 3%. let y represent the original price of the dvd. write an expression that can be used to determine the final cost of the dvd.

Percent means parts out of 100, remember that

12% off

12% off means 100%-12%=88%
find 88% of that
then take 3% and addd that
3% off of 100=100+3=103% of that

then

so original price=p
find 88% of that then 103% of that

p*0.88*1.03=final cost
p*0.9064=final cost
0.9064p=final cost

Let normal price=y
Let modified price=x
12% off=88% of normal price, without tax=.88*x without tax.
Tax=additional 3%=1.03*price=1.03*.88*x=.9064x
Since .9064x is our final modified price, the equation is 
y=.9064x
y=1.03*                               .88*                   x
     ^ Sales tax multiplier      ^12% off sale   ^ original price

Hope this helps!

2pounds will cost $1.96