下面各题,怎样简便就怎样算.[的/5]+[2/5]×[5/九][的/7]×[下/4]+[4/7]÷4

1个回答

  • 解题思路:(1)先算乘法,再算加法;

    (2)根据乘法分配律进行简算;

    (3)根据乘法分配律进行简算;

    (4)根据除法的性质进行简算;

    (5)先算减法,再算加法.最后算除法;

    (6)先算除法,再算减法,最后算乘法.

    (1)[i/i]+[1/i]×[i/6]

    =[i/i]+[1/i]

    =[14/1i];

    (1)[i/7]×[1/4]+[4/7]÷4

    =[i/7]×[1/4]+[4/7]×[1/4]

    =([i/7]+[4/7])×[1/4]

    =1×[1/4]

    =[1/4];

    (i)4.i×14.1

    =4.i×(14+4.1)

    =4.i×14+4.i×4.1

    =4i+4.4i

    =4i.4i;

    (4)416÷1i÷4

    =416÷(1i×4)

    =416÷144

    =4.16;

    (i)[9/11]÷[[1/i]+(1-[14/11])]

    =[9/11]÷[[1/i]+[1/11]]

    =[9/11]÷[17/ii]

    =[i/i];

    (6)(i.个-1.个÷1)×4.i

    =(i.个-1.4)×4.i

    =1.4×4.i

    =4.71.

    点评:

    本题考点: 分数的四则混合运算;小数四则混合运算.

    考点点评: 考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.