2×2.39-0.13-1
问题描述:
2×2.39-0.13-1
———————
2.39+2×0.13+1
答
[2(2+3×0.13)-0.13-1]÷[(2+3×0.13)+2×0.13+1]
=(3+5×0.13)÷(3+5×0.13)
=1