Question

Efectuați:
a) (-1) x (-1)^2 x (-1)^3 x....x (-1)^20=
b) (-1) + (1)^2 + (-1)^3 +.....+ (-1)^20=
Am nevoie urgent de răspuns! Va rog frumos! ​

Answer 1

Salut! :)

a) ( - 1 ) × ( - 1 )² × ... × ( - 1 )²⁰ =

( - 1 )¹ + ² + ... + ²⁰ =

( - 1 )²⁰ × ²¹ : ² =

( - 1 )¹⁰ × ²¹ =

( - 1 )²¹⁰ = 1

b) ( - 1 ) + ( - 1 )² + ... + ( - 1 )²⁰ =

( - 1 + 1 ) + ( - 1 + 1 ) + ... + ( - 1 + 1 ) = 10 × 0 = 0

c) ( - 1 ) - ( - 1 )² - ... - ( - 1 )²⁰ =

- 1 + ( - 1 + 1 ) + ... + ( - 1 + 1 ) - 1 =

- 2 + 9 × 0 = - 2 + 0 = - 2

d) ( - 2 ) × ( - 2 )² × ... × ( - 2 )²⁰ : ( - 8 )⁷⁰ =

( - 2 )²¹⁰ : ( - 2³ )⁷⁰ =

( - 2 )²¹⁰ : ( - 2 )²¹⁰ = 1