6.4×(7/4-1.25)×1/10=6.4×(1.75-1.25)×1/10=6.4×0.5×1/10=3.2×1/10=0.32所以,可以括号里面的7/4化为1.75,然后进行计算。
原式=6.4×(7/4-5/4)×1/10=6.4×2/4×1/10=6.4×1/2×0.1=3.2×0.1=0.32
6.4×(7/4-1.25)×1/10=6.4x(7/4-5/4)x1/10=6.4x2/4x1/10=6.4x0.5x0.1=0.32