Ok, no worries, I can break it down more.
When you want to convert a temperature in Celsius to a temperature in Fahrenheit, multiply the temperature in Celsius by 1.8, then add 32. The result will be that temp in Fahrenheit.
If you want to do the opposite and convert a temperature in Fahrenheit to a temperature in Celsius, you would first subtract 32 from the temperature in Fahrenheit, then multiply it by the fraction 5/9. The result will be that temp in Celsius.
So in the first example, I was converting to Fahrenheit, so I took the temp in Celsius (10°), and multiplied it by 1.8, which equals 18. Then I added 32, which equals 50, which means that 10 degrees Celsius is the same as 50 degrees Fahrenheit.
Edited to add one of the examples.