Hey there! I'm happy to help!
Let's convert the decimals to fraction form.
0.5=5/10=1/2
-1/7
-0.2= -2/10= -1/5
1/3
We know that the bigger the number in the denominator, the smaller the fraction is if the numerators are all the same.
First off, we have the negative numbers which are smaller than the other numbers. We have -1/7 and -1/5. We know that the 1/5 is a bigger fraction, but it is negatively bigger, so that is going to be the lesser number.
-1/5, -1/7
And with our bigger ones, we have 1/3 and 1/2. 1/2 is the bigger number here, so that will be the last one. Let's also be sure to convert back to our original forms! Here is our order :
-0.2, -1/7, 1/3, 0.5
Have a wonderful day and keep on learning! :D