Question

Daca A= 2x(1+2+3+4+...+2021)+2022 atunci A:2022 este:

Answer 1

Răspuns:

Salutare!

A=2×(1+2+3+..+2021)+2022

A=2×(2021•2022/2)+2022

A=2×(4086462/2)+2022

A=2×2043231+2022

A=4086462+2022

A=4088484

A:2022=4088484:2022=2022

Answer 2

A = 2 * (1+2+3....+2021) + 2022

1 + 2 + 3 + .... + 2021 ( suma lui Gauss) : 2021 * 2022 / 2

A =

$2 \times \frac{2021 \times 2022}{2} + 2022$

= 2021 * 2022 + 2022 = 2022 * ( 2021 + 1) = 2022 * 2022

A : 2022 = 2022 * 2022 : 2022 = 2022