①(+7.4)-(+3.6)=7.4-3.6=3.8②(-25.9)÷(-7)=25.9÷7=3.7③[0.15+(3.74-1.8)÷0.4]×20=[0.15+1.94÷0.4]×20=[0.15+4.85]×20=5×20=100④(1-0.8)×(4-3.68)÷0.01 =0.2×0.32×100=6.4⑤76.14-12.28-16.72 =76.14-(12.28+16.72)=76.14-29=47.14⑥7.5-7.5×0.99=7.5×(1-0.99)=7.5×0.01=0.075⑦6.3×18.5+18.5×3.7 =18.5×(6.3+3.7)=18.5×10=185⑧6.78÷0.8÷0.125 =6.78÷(0.8×0.125)=6.78÷0.1=67.8⑨8.9÷1.25=8.9×8÷(1.25×8)=71.2÷10=7.12