新野旁观者 知道合伙人
数学类认证行家 2017-11-15
0.34×2-0.34×2/7+1/3×(-3)-5/7x0.34
=0.34×(2-2/7-5/7)+1/3×(-3)
=0.34×1-1
=0.34-1
=-0.66
0.34×2-0.34×2/7+1/3×(-3)-5/7x0.34
=0.34×(2-2/7-5/7)+1/3×(-3)
=0.34×1-1
=0.34-1
=-0.66
。。
13×2/3-0.34×(-2/7)+1/3×13+5/7×0.34
=13×2/3+1/3×13+5/7×0.34-0.34×(-2/7)
=13(2/3+1/3)+0.34[5/7-(-2/7)]
=13+0.34
=13.34