①(1234567+2345671+3456712+4567123+5671234+6712345+7123456)/7=?

问题描述:

①(1234567+2345671+3456712+4567123+5671234+6712345+7123456)/7=?
②(1+1/2)x(1+1/4)x(1+1/6)x...x(1+1/10)x(1-1/3)x(1-1/5)x...x(1-1/9)=?

第一题=(1111111+2222222+3333333+...+7777777)/7=(1111111*(1+2+3+...+7))/7=1111111*28/7=4444444第二题=(3/2*5/4*...*9/8*11/10)*(2/3*4/5*...8/9)=3/2*2/3*5/4*4/5*.=11/10