According to Conversion formula above if you want to convert degrees Celsius to degrees Fahrenheit you have to multiply degrees Celsius by 9, divide the result by 5 and add 32 to it.
So you have: ((42 × 9) ÷ 5) + 32 = (378 ÷ 5) + 32 = 75.6 + 32 = 107.6 °F
