Question

(4+8+12+16+...+100)/(2+4+6+...+50)=

Answer 1

[tex] S=\frac{4+8+12+16+...+100}{2+4+6+..+50} \\ S= \frac{4(1+2+3+4+...+25)}{2(1+2+3+...+25)}\\ \text{Se oberva ca sumele se simplifica}\\ S= \frac{4}{2}=2 [/tex]

Answer 2

_(4+ 8+12+16+ ... + 100)_ =
       (2+ 4+ 6+ ... +50)


_(1·4+ 2·4+ 3·4+ 4·4+ ... +25·4)_ =
       (1·2+ 2·2 + 3·2+ ... +25·2)
 

_4·(1+ 2+ 3+ 4+ ... +25)_ =
  2·(1+ 2+ 3+ 4+... +25)

_4_
  2

2