(2.5×8.8+2.5×0.8)×1.25 =2.5×(1.1+0.1)×0.8×1.25 =2.5×12×1 =2.5×2×6 =5×6 =30
2.5*（4*0.6*4）*1.25=（2.5*4）*0.6*（4*1.25）=10*0.6*5=6*5=30
解： 7.9*1.25 =(8-0.1)*1.25 =8*1.25-0.1*1.25 =10-0.125 =9.875
