In this case, How can I solve this kind of problem?
Ex:
.036 (bar over or repeating decimal - 36)
.03 (bar over or repeating decimal - 3)
.659 (bar over or repeating decimal - 59)
20.435 (bar over or repeating decimal - 35)
The key with these is to isolate the repeating portion. We will use the same process that is demonstrated on the page from the screenshot you provided (though it’s cut off in the screenshot).
Notice that instead of subtracting x (like they do in the examples), we end up subtracting 10x instead, because that is what isolated the repeating portion that we are interested in.
Because all of the given examples have their repeats one decimal place away, you can follow the same strategy of subtracting 10x—but remember that the point is to isolate the repeating portion, so adjust the strategy accordingly if you’re solving for a number where the repeating digits are more decimal places away.