Answer
$-78^oC=-108.4^oF.$
Work Step by Step
To change from degrees Celsius to degrees Fahrenheit, we use the formula $$F=\frac{9}{5}C +32^o=\frac{9}{5}( -78^o)+32^o=-108.4^o$$ that is $-78^oC=-108.4^oF.$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.