Question

tính nhanh:

(1/2+2/3+3/4+4/5+...+122/123+123/124).(125-5.25)

Answer 1

(1/2+2/3+3/4+4/5+...+122/123+123/124).(125-5.25)

=(1/2+2/3+3/4+4/5+...+122/123+123/124).(125-125)

=(1/2+2/3+3/4+4/5+...+122/123+123/124).0=0