初一解方程去分母特难题(计算)最好有答案.

问题描述:

初一解方程去分母特难题(计算)最好有答案.
十道起,后五道追加2分,再后5道加4分,以此类推

(3-x)/(2x-4)/(x+2-5/x-2)
=(3-x)/2(x-2)÷(x²-4-5)/(x-2)
=(3-x)/2(x²-9)
=(3-x)/2(x-3)(x+3)
=-1/(2x+6)
(x²+6x+9)/(x²-x-6)/(x²-9)/(x²-3x-10)*(x-3)/(x-5)
=[(x+3)²/(x-3)(x+2)]/(x-3)(x+3)/(x-5)(x+2)*(x-3)/(x-5)
=(x+3)/(x-3)