36.8-3.9-6.12=36.8-（3.9+6.12）=36.8-10.02=26.785.6÷3.5=56/35=8/55.48-（9.4-0.52）=5.48-9.4+0.52=5.48+0.52-9.4=6-9.4=-3.4
一步步解就行了
