Question

Efectuati: (4+8+12+... +200)÷(2+4+6+... +100)
Dau coroana si 100 puncte

Answer 1

(4+8+12+... +200) = 4 (1+2+3+...+50) = 4*50*51/2 = 5100

2+4+6+... +100 = 2 (1+2+3...+50) = 2*50*51/2 = 2550

5100 : 2550 = 2

sau ...

(4+8+12+... +200) : (2+4+6+... +100) = 4 (1+2+3+...+50) : 2 (1+2+3...+50)  = 2

Answer 2

(4+8+12+... +200)÷(2+4+6+... +100)=

4 x (1 + 2 + 3 +.....+50) : 2 x (1 + 2 +3+ ...+50) =

se simplifica  prima paranteza cu a doua paranteza =

4 : 2 =

2