17.6+10.5÷(5.2-3.5)=17.6+10.5÷1.7=(17.6x1.7+10.5)÷1.7=((17.6x2-17.6x0.3)+10.5)÷1.7=((35.2-5.28)+10.5)÷1.7=(29.92+10.5)÷1.7=40.42÷1.7=2021/85
17.6+10.5÷(5.2-3.5)=17.6+10.5÷8.7=88/5+35/29=(2552+175)/145=2727/145