原式=[2×（2+0.13×3）-0.13-1]/[(2+0.13×3)+2×0.13+1]
=[0.13×5+3]/[0.13×5+3]
=1
思想就是把2.39拆成2+0.13×3这样就能合并了
一道能巧算的计算题.（2×2.39-0.13-1）/（2.39+2×0.13+1）这题可以巧算,但我不会巧,麻烦各位把巧
原式=[2×（2+0.13×3）-0.13-1]/[(2+0.13×3)+2×0.13+1]
=[0.13×5+3]/[0.13×5+3]
=1
思想就是把2.39拆成2+0.13×3这样就能合并了