计算 1/2+1/6+1/12+1/20+1/30.+1/110
问题描述:
计算 1/2+1/6+1/12+1/20+1/30.+1/110
1/2+1/6+1/12+1/20+1/30.+1/110 写出计算过程
答
1/2 = 1/1*2 = 1/1-1/21/6 =1/2*3 = 1/2-1/31/12 = 1/3*4 = 1/3-1/4.1/90 = 1/9*10 = 1/9 - 1/101/110 = 1/10*11 = 1/10 -1/11所以原式=1/1-1/2+1/2-1/3+1/3.-1/9+1/9-1/10+1/10-1/11=1-1/11=10/113/4��x+2.8��=75�����Ŀ��ô��3/4��x+2.8��=753/4xʮ2.1=753/4x=72.9x=97.2