(14.23加16.17)乘0.8簡便計算

(14.23加16.17)乘0.8簡便計算

(14.23+16.17)乘0.8=(14+0.23+16+0.17)乘0.8=【(14+16)+(0.23+0.17)】乘0.8=(30+0.4)乘0.8=(30乘0.8)+(0.4乘0.8)=24+0.32=24.32