Compute the sum
(a+(2n+1)d)2−(a+(2n)d)2+(a+(2n−1)d)2−(a+(2n−2)d)2+⋯+(a+d)2−a2.
See answer #2 here: https://web2.0calc.com/questions/please-help-question-not-answered#r2
thx so much
