Question

Exercițiul 9 urgenttttt !
Dau coroana ! ​

Answer 1

Răspuns:

a)3/153+6/153+9/153+...+99/153=

=3+6+9+...+99/153

=3(1+2+3+...+33)/153

=3(33×34/2)/153

=3(33×17)/153

=3×561/153=11

b)6/357+9/357+12/357+102/357

6+9+12+...+102/357

3(2+3+4+..+34)/357

3(+1+2+3+4+...+3+34×1)/357

3(33×34/2 +34)/357

3(33×17 +34)/357

3(561+34)/357

3×595/357=5

Answer 2

Răspuns:

a)(3/153)(1+2+3+...+99)=

(1/51)×99(99+1)/2=(1/51)99×100×(1/2)

(1/102)×9900=4950/51

b)(3/357)×(2+3+4+...+34)=

(1/119)×(1-1+2+3+...+34)=

34×35/2×119=17×35/119=35/7=5