Question

找规律计算:3/4+3/28+3/70+3/130+3/208=?

Answer 1

15/16

3/4=1/1-1/4

3/28=3/(4*7)=1/4-1/7

3/70=1/10-1/13

3/130=1/10-1/13

3/208=1/13-1/16

所以相加,中间的项都抵消了,原式=1-1/16=15/16

或

3/4+3/28+3/70+3/130+3/208

=(1-1/4)+(1/4-1/7)+(1/7-1/10)+(1/10-1/13)+(1/13-1/16)

=1-1/16

=15/16

知道了吗?祝你学习进步!