To simplify the expression properly, let's break it down step by step:
Step 1: Simplify the multiplication of fractions
3/5 x 13.65 = (3 x 13.65) / 5 = 40.95 / 5 = 8.19
2/9 x 1.307 = (2 x 1.307) / 9 = 2.614 / 9 = 0.29044 (rounded to five decimal places)
Step 2: Subtract the results obtained from step 1
8.19 - 0.29044 = 7.89956
Step 3: Round the final result to the desired number of decimal places
Since the original numbers provided have four decimal places, it would make sense to round the final result to the same level of precision.
Rounding 7.89956 to four decimal places gives us 7.8996.
So, the simplified answer is 7.8996, rounded to four decimal places.