Question

Va rog urgent
0,2+0,4+0,6+...+1,8
dau 12pct si coroana

Answer 1

Răspuns:

Explicație pas cu pas:

0.2+0.4+0.6+0.8+1+1.2+1.4+1.6+1.8

0.6+1.4+2.2+3+1.8

2+5.2+1.8

7.2+1.8

9

Answer 2

$0.2 + 0.4 + 0.6 + ... + 1.8$

$=0.2(1 + 2 + 3 + ... + 9)$

$= 0.2 \times \frac{9(9 + 1)}{2} = 0.2 \times \frac{9 \times 10}{2}$

$= 0.2 \times 9 \times 5 = 0.2 \times 5 \times 9 = 1 \times 9 = 9$