Question

To change from degrees celsius to degrees fahrenheit, you can use the equation f=9/5c+32. If the temperature is at least 55 degrees fahrenheit, what inequality can you use to find the temperature in celsius?

a) 55> 9/5c+32
b) f>9/5 x 55+32
c) 55<9/5c+32
d) f<9/5 x 55+32

Answer 1

\[\Large\bf\sf f=\frac{9}{5}c+32\]

If the temperature `f` is `at least` 55,
this translates to `f` is `greater than or equal to` 55.
\[\Large\bf\sf \color{royalblue}{f}\ge55\]Plugging in our function for f gives,
\[\Large\bf\sf \color{royalblue}{\frac{9}{5}c+32}\ge55\]

Answer 2

Err hmm.. I guess your options have the 55 written on the left side..

Answer 3

So if we flip it around to read it from the other direction,
\[\Large\bf\sf 55\le \frac{9}{5}c+32\]

This look like any of them? :o

Answer 4

Thank you! @zepdrix