how do i solve the sum of the first n even positive integers is h. the of the first n odd positive integers is k. determine the value of h-k, in terms of n

for n = 3

h = 2+4+6 = 12
k = 1+3+5 = 9
-------------- subtract
h-k 1+1+1 = 3

h - k = 3 for n = 3
In fact you get one more for every increase of n by 1
so
ah ha
h-k = n