17 18 两题
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![17 18 两题](/uploads/image/z/5899623-15-3.jpg?t=17+18+%E4%B8%A4%E9%A2%98)
17 18 两题
17 18 两题
17 18 两题
17半个.
18 (3x+4)/(x-1)(x+1)-2(x+1)/(x-1)(x+1)*(x-1)2/(x+2)
=(3x+4-2x-2)/(x-1)(x+1)*(x-1)2/(x+2)
=(x+2)/(x-1)(x+1)*(x-1)2/(x+2)
=(x-1)/(x+1)
=(-3-1)/(-3+1)
=-4/-2
=2
童鞋给个采纳