Question

2+4+6...+222=? dau coroana si foarte repede

Answer 1

S=2+4+6+...+222
S= 2(1+2+3+4+...+111)
S= 2 × $\frac{111*112}{2}$
S=2×$\frac{12432}{2}$
S=2 ×6216
S=12432

Answer 2

$\displaystyle 2+4+6+...+222=2(1+2+3+...+111)=\not2 \cdot \frac{111(111+1)}{\not2} = \\ \\ =111 \cdot 112=\boxed{12432}$