Equation = 0?

[dawn radish]

Doesn't the following equation = 0? I don't know how you would simplify it? What would be the first step to calculate?

[violet badge]

Do N have any value

Or is it natural number

@dawn radish

[eternal grotto]

N seems to be a natural number since the sum goes from 1 to N, i only takes integer values

[violet badge]

There might be multiple possibilities then?

[eternal grotto]

there is the case when a1=a2=...=an
or when b1=...=bn
for which this expression is 0

but it is not 0 in general case
https://en.m.wikipedia.org/wiki/Chebyshev's_sum_inequality

you multiply the two sums by the distributive law