Answer:
To solve for n you need to get it by itself
First you want to distribute your 2 through the (3n+14)
-2n+6n+28=-20 (2*3n+2*14= 6n+28)
Now you want to combine any like terms if possible
4n+28=-20 (-2n+6n=4n, both like terms)
Then you want to subtract -28 from both sides
4n=-48 (28-28=0, -20-28=-48)
Lastly you want to divide both sides by 4
n=-12 (4n/4=n, -48/4= -12)
If you do 5 divide by 4 then you can find what 1$ would be worth so ie.
5 divide by 4 is 1.25 which means that for 1$ you could buy 1.25 ounces