0.9-（0.15+0.35÷5/7）=0.9-(0.15+0.35×7/5)=0.9-(0.15+0.49)=0.9-0.64=0.264/9x[3/4-(7/16-1/4)]=4/9×[3/4-7/16+1/4]=4/9×(1-7/16)=4/9×9/16=1/45/4x3/5÷3/2x2/3=3/4÷3/2×2/3=1/2×2/3=1/3[800+(280-240÷3...