计算:(x+1)(x+2)分之1+(x+2)(x+3)分之1+(x+3)(x+4)分之1+(x+4)(x+5)分之1
问题描述:
计算:(x+1)(x+2)分之1+(x+2)(x+3)分之1+(x+3)(x+4)分之1+(x+4)(x+5)分之1
答
1/((x+1)(x+2))+1/((x+2)(x+3))+1/((x+3)(x+4))+1/((x+4)(x+5))=((x+3)(x+4)(x+5)+(x+1)(x+4)(x+5)+(x+1)(x+2)(x+5)+(x+1)(x+2)(x+3))/((x+1)(x+2)(x+3)(x+4)(x+5))=((x+4)(x+5)(2x+4)+(x+1)(x+2)(2x+8))/((x+1)(x+2...