7+5.4+4.65.7+3.5+6.5
8.6+(3.4+6.6)(8.6+3.4)+6.6
20-4.19-5.8120+4.19-5.81
(4.7+5.3)+7.87.8+(5.3+4.7)
35.6+4.6+7.0135.6+4.4+7.21