Question

\(2^{n+2}-2^n=\) 6

Answer 1

ta có 2ⁿ⁺² - 2ⁿ = 6

Suy ra 2ⁿ . 2² - 2ⁿ . 1 = 6

Suy ra 2ⁿ . (2² - 1)=6

Suy ra 2ⁿ . (4-1)=6

Suy ra 2ⁿ . 3=6

Suy ra 2ⁿ = 6:3

Suy ra 2ⁿ = 2

Suy ra 2ⁿ = 2¹

Suy ra n=1

Vậy, n=1

Tick nha

Answer 2

\(2^{n+2}-2n=6\)

=>\(2^n\left(2^2-1\right)=6\)

=>\(3.2^n=6\)

=>\(2^n=2\)

Vì 2 khác -1;0;1 nên \(n=1\)

Vậy...