The sales tax in one state is 7% .write a function rule for the total cost of an item with selling price x. then find the total cost of a cd player with a selling price of $150.

a) f(x)= 0.07x; $10.50
b) f(x)= 1.07x; $160.50
c) f(x)= 7+x; $151.07
d) f(x)= x-7; $148.93

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

How do i do this? i don’t understand

Trent wants to buy 2 packs of trading cards for 3 dollars each. the trading card packs that trent normally buys tend to come in packs of 6, 10, 12, or 15 cards. after selecting 2 packs, trent found that the first pack of cards cost 25 cents per card, and the second pack cost 30 cents per card. trent uses this information to write the equations below in order to compare c, the number of cards in each pack.