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.... 
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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.
36.89 total divided by the 8.6 gallons he bought = 4.2 so the price per gallon would be $4.20
x ≤ 2.6 would look like this on the number line, the 2.6 part would be shaded in as well and not left open since x is less than OR EQUAL to 2.6
Answer:
D. The function f has 3 horizontal tangent lines
Step-by-step explanation:
Well whenever any function crosses the x-axis, it means that the y-value is equal to zero.
In this case when the derivative passes the x-axis it indicates the tangent line corresponding to that x-value has a slope of zero, which when plotted is a horizontal line.
This means that the graph f has 3 horizontal tangent lines.