2个数学题.小学的

来源:百度知道 编辑:UC知道 时间:2024/05/14 17:12:29
1.(1+1/99+3又5/33+9又5/11)÷(1又1/99+3又1/33+9又1/11)
2.(3+5/9-2/3)×(1/6+1/9+1/12)-(1/6-1/9+1/12)×3+(1/6+1/9+1/12)×(2/3-5/9)
须简算!!!

×÷

1、=(99+1+(99*3+5*3)+(9*99+5*9))/99*99/100+99*3+3+9*99+9
=(100+312+936)/(100+300+900)
=1348/1300
2、=(1/6+1/9+1/12)×(3+5/9-2/3-3+2/3-5/9)
=(1/6+1/9+1/12)×0
=0

很简单,第一道题在分子分母上乘以99,(99×(1+1/99+3又5/33+9又5/11))÷(99×(1又1/99+3又1/33+9又1/11))=(99+1+312+936)÷(100+300+900)=1348÷1300
=337/325

(3+5/9-2/3)×(1/6+1/9+1/12)-(1/6-1/9+1/12)×3+...........
=(1/6+1/9+1/12)×{(3+5/9-2/3)+(2/3-5/9)}-(1/6-1/9+1/12)×3
==(1/6+1/9+1/12)×{3+5/9-6/9+6/9-5/9}-(1/6-1/9+1/12)×3
=(1/6+1/9+1/12)×{3+5/9-6/9+6/9-5/9-3}
=0

第二题:
(3+5/9-2/3)×(1/6+1/9+1/12)-(1/6-1/9+1/12)×3+(1/6+1/9+1/12)×(2/3-5/9)
=(1/6+1/9+1/12)*(3+5/9-2/3+2/3-5/9)-(1/6-1/9+1/12)*3
=(1/6+1/9+1/12)*3-(1/6-1/9+1/12)*3
=3*(1/6+1/9+1/12-1/6+1/9-1/12)
=3*2/9
=2/3