Answer:
y=-x-0.833.....
Step-by-step explanation:
You solve for Y in the first two and then solve for x in the last two parts of the problem.
You Just want to get Fahrenheit alone on one side of the equal sign. Your teacher forgot to use parenthesis. The correct equation for Celsius to Fahrenheit is:
Which will give you a completely different answer.... 
****
We will solve it using what is given:
C = (5/9)F - 32
C + 32 = (5/9)F
9(C + 32) = 5F
(9/5)(C + 32) = F
** If they mark you wrong, and try to say the answer is F = (9/5)C + 32 then they shouldn't be teaching math, and you should point out the fact there are no parenthesis around the F - 32 in the given formula.
If you think of the equation as an equation for a line.
y=mx+b
y
=
m
x
+
b
where
C=5/9(F−32)
C
=
5
/
9
(
F
−
32
)
or
C=5/9F−5/9(32)
To find the percent of increase get the difference between the prices and then divided by the oringinal price and then time that by 100
increase =