Step 1:
The first step to converting 128991928.71657 to a fraction is to re-write 128991928.71657 in the form p/q where p and q are both positive integers. To start with, 128991928.71657 can be written as simply 128991928.71657/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 128991928.71657, which in this case is 5. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 128991928.71657/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 128991928.71657/1 each by 100000:
Step 3:
Now the last step is to simplify the fraction (if possible) by finding similar factors and cancelling them out, which leads to the following answer for 128991928.71657 as a fraction:
128991928/1 / 1