简便计算: 2.5×3.2×12.5 6.3÷1.4 2.5×2.4 15.32×4+4.68÷0.25 2.55×1.5+1.5+6.45×1.5 2.95×101-2.95 3.12+3.12×99 15÷(0.15×0.4) 2.55×1.5+1.5+6.45×1.5 73.8-1.64-13.8-5.36 6.75-(0.9+3.75) 27.38-5.34+2.62-4.66 35.72-4.9-(5.72+5.1) 0.73-0.25-0.73+0.25 5.3+0.1+5.3-0.1 12.7-4.8-5.2.