Question

Care știe sa rezolve , dau coroana

Answer 1

3. 5291÷13= 407 timbre pentru fiecare

4. 2011+9999×2011=

2011(1+9999)=

2011×10000=20110000 (sau 2011×10^4

5. 2+4+6+...+88=

2(1+2+3+...+44)=

2× (44×45)/2 (×2 ÷2 se reduc)

44×45=1980

sper ca te ajutaa

Answer 2

$\bf{3.}\ \ \ \it 6291:13=407\ timbre\ a \ primit\ fiecare\\ \\ \bf{4.}\ \ \ \it 2011+9999\cdot2011=2011\cdot(1+9999)=2011\cdot10000=20110000 \\ \\ \bf{5.}\ \ \ \it 2+4+6+\ ...\ +88=\dfrac{(2+88)\cdot44}{2}=90\cdot22=1980$