1.58*0.58+0.42*0.42+1.16*0.42怎樣簡算1.58*0.58+0.42*0.42+1.16*0.42怎樣簡算

1.58*0.58+0.42*0.42+1.16*0.42怎樣簡算1.58*0.58+0.42*0.42+1.16*0.42怎樣簡算

1.58*0.58+0.42*0.42+1.16*0.42
=1.58*0.58+0.42*(0.42+1.16)
=1.58*0.58+0.42*1.58
=1.58*(0.58+0.42)
=1.58*1
=1.58