2、用递等式计算.(能简算要简算)写过程.

1个回答

  • 4.67-(2.98+0.67)

    =4.67-2.98-0.67

    =(4.67-0.67)-2.98

    =4-2.98

    =1.02

    73.8x16-73.8x6

    =73.8×(16-6)

    =73.8×10

    =738;

    (5分之4+4分之1)÷3分之7+10分之7

    =(16/20+5/20)×(3/7)+7/10

    =(21/20)×(3/7)+7/10

    =9/20+14/20

    =23/20;

    (1-4分之1-12分之5)÷3分之2

    =(1-1/4-5/12)×(3/2)

    =(12/12-3/12-5/12)×(3/2)

    =(4/12)×(3/2)

    =1/2;

    9分之8x[7分之3÷(3分之2+7分之1)]

    =(8/9)×[(3/7)÷(17/21)]

    =(8/9)×(3/7)×(21/17)

    =8/17;

    18.8-5分之2-5.8-5分之3

    =(18.8-5.8)-(2/5+3/5)

    =13-1

    =12;

    3、化简下面各比. 写过程

    12.6:0.4=126:4=63:2;

    20分之1:6分之5=6:100=3:50;

    2分之1吨:450千克=500:450=10:9;

    2.5小时:40分=2.5×60:40=150:40=15:4;

    4、求未知数X. 写过程.

    X:0.25=81:75

    75x=81×0.25;

    x=81/4×(1/75);

    z=81/200;

    4分之1:12分之1=8:X

    x/4=8/12;

    x=8/3;

    4X-2.5X=0.75;

    1.5x=0.75;

    x=0.5;

    5.5+3X=8.5

    3x=3;

    x=1;