Question

calculați 4+6+8....68

Answer 1

Ne folosim de suma lui Gauss

2+4+6+...+68=2(1+2+3+...+34)=2x34x35:2=1190
4+6+8....68=(2+4+6+...+68)-2=1190-2=1188

Answer 2

4 + 6 + 8 +...+ 68 =
Aflam cati termeni are suma:
(68 - 4): 2 + 1 = 64:2+1 = 32+1 = 33

= (4+68) × 33 : 2 =

= 72 ×33 :2 =

= 36×33 =

= 1 188