(200-10((x-10)/0.5)))*(x-8)=640怎么计算？

来源：百度知道编辑：UC知道时间：2024/05/25 19:26:14

答案是12和16.

先化解再求值.
先开最里面的括号,依次下去
1:(200-10(2x-20))(x-8)=640
2:(200-20x+200)(x-8)=640
3:(200-20x+200)(x-8)=640
4:(-20x+400)(x-8)=640
5:(-20x+400)(x-8)=640
6:x^2-28x+192=0
7:(x-14)^2=4
8:x1=+2+14=16 x2=-2+14=12

讲得太细了`晕~

(200-10((x-10)/0.5))(x-8)=640
化简得：
x^2-28x+192=0
(x-12)(x-16)=0

x1=12
x2=16

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