Answer:
c ≈ -29°
Step-by-step explanation:
To convert Fahrenheit to Celsius using the formula, substitute the degrees for Fahrenheit "f", then isolate Celsius "c".
f = [tex]\frac{9}{5}c[/tex] + 32
-20 = [tex]\frac{9}{5}c[/tex] + 32 Substitute "f" for -20
-20 - 32 = [tex]\frac{9}{5}c[/tex] + 32 - 32 Subtract 32 from both sides
-20 - 32 = [tex]\frac{9}{5}c[/tex] +32-32 cancels out to 0. Simplify left side
-52 = [tex]\frac{9}{5}c[/tex]
-52/[tex]\frac{9}{5}[/tex] = [tex]\frac{9}{5}c/\frac{9}{5}[/tex] Divide by 9/5 on both sides
-52/[tex]\frac{9}{5}[/tex] = c
-52[tex]*\frac{5}{9}[/tex] = c When dividing a fraction, flip the fraction and change to multiplication
[tex]\frac{-52*5}{9}[/tex] = c Multiply by combining into the numerator
[tex]\frac{-260}{9}[/tex] = c Use a calculator
c = -28.8888888889°
c ≈ -29° Round to the nearest degrees
Therefore -20°F is about -29°C.
