Convert minus 40 degrees to minus 40 degrees Fahrenheit
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To convert from Celsius to Fahrenheit, multiply the Celsius value by 9 and divide the product by 5. To this obtained value, add 32. Therefore, –40 Celsius is equal to –40 × 9 = –360; –360 ÷ 5 = –72; –72 + 32 = –40 degrees Fahrenheit.