1.5×[19/21÷6又1/3×（0.7－0.66）]×4.9=?急 谢

1.5×[19/21÷6又1/3×（0.7－0.66）]×4.9=?急 谢
1.5×[19/21÷6又1/3×（0.7－0.66）]×4.9=?急 谢

1.5×[19/21÷6又1/3×（0.7－0.66）]×4.9=?急 谢
=1.5*[19/21÷6又1/3*0.04]*4.9
=1.5*[19/21*3/19*0.04]*4.9
=1.5*0.04*4.9/7
=0.42

no

=1.5*〔19/21*3/19*(7/10-66/100)*49
=1.5*[1/7*7/10-1/7*66/100)*49
=1.5*4/700*49
=42/100
=0.42

=1.5*〔19/21*3/19*(7/10-66/100)*49
=1.5*[1/7*7/10-1/7*66/100)*49
=1.5*4/700*49
=42/100
=0.42

1.5×[19/21÷6又1/3×（0.7－0.66）]×4.9=0.042
过程：
6又1/3=19/3 这你知道吧
1.5×[19/21×3/19×0.04]×4.9 这个中括号可以去掉
=1.5×19/21×3/19×0.04×4.9 可以移动一个顺序
=1.5×0.04×19/21×3/19×4.9 19/21×3/19=1/7
=0.06×1/7×4.9
=0.06×0.7
=0.042