Question

n=1 +2+3+...+109-55*54

Answer 1

N=1+2+3+....+109-55X54
N=109x(109+1):2-55x54
N=109x110:2-55x54
N=109x55-55x54
N=55(109-54)
N=55x55
N=55^2
N=3025

Answer 2

N=(1+109)·109:2-55·54
N=110·109:2-55·54
N=55·109-55·54
N=55(109-54)
N=55·55
N=3025