kill(all)$

van=facebook.com/LearningCalculus$

f(n):=binomial(2*n,2) = 2*binomial(n,2)+n^2;

lhs(f(n));

rhs(f(n));

left:expand(lhs(f(n)));

rite: expand(rhs(f(n)));

is(equal(left,rite));

lhs(f(n));

expand(%);