Question

efectuati:
1+3+5+...+99
___________
2+4+6+...+100​

Answer 1

Răspuns:

1+3+5+99=108

2+4+6+100=112

Answer 2

Răspuns:

1+3+5+...+99 = (2*1-1)+(2*2-1)+...+(2*50-1) = 2(1+2+3+..+50)-(1+1+1+...+1)

= 2* 50*51:2 -1*50 = 50*51-50 = 2500

2+4+6+...+100= (2*1)+(2*2)+(2*3)+.,..+(2*50) = 2(1+2+3+4+...+50) =

= 2*50*51:2 = 50*51 = 2550

Explicație pas cu pas: