Question

1-1/2的绝对值+1/2-1/3的绝对值+1/3-1/4的绝对值+...+1/9-1/10的绝对值

Answer 1

∣1-1/2∣+∣1/2-1/3∣+∣1/3-1/4∣+.+∣1/9-1/10∣

=1-1/2+1/2-1/3+1/3-1/4+.+1/9-1/10

=1-1/10

=9/10