Răspuns :
Desfacand paranteza si inmultind fiecare numar cu 100 vom obtine 1+2+3+....+9= 9•10:2=9•5=45
(0.09-0.01):1+1= 0.08+1=0.09
(0.09+0.01)x0.09= 0.1*0.09=0.009
100x0.009= 0.9
(0.09+0.01)x0.09= 0.1*0.09=0.009
100x0.009= 0.9