Question

1. Tìm số tự nhiên x biết:

\(3.2^x+12=4.3^2\)

Giúp mik mn ơi, hứa k cho

Answer 1

3. 2^x +12 =4.3²

=> 3. 2^x +12= 36

=> 3 . 2^x = 24

=> 2^x = 8 => x = 3

vậy x = 3

Answer 2

\(3.2^x+12=4.3^2\)

\(\Rightarrow3.2^x+12=4.9\)

\(\Rightarrow3.2^x+12=36\)

\(\Rightarrow3.2^x=36-12\)

\(\Rightarrow3.2^x=24\)

\(\Rightarrow2^x=24\div3\)

\(\Rightarrow2^x=8\)

\(\Rightarrow2^x=2^3\)

Vậy x = 3

Answer 3

3.2^x + 12 = 4.3² 

<=> 3.(2^x + 4) = 4.3² 

<=> 2^x + 4 = 12

<=> 2^x = 8

<=> 2^x = 2³ 

<=> x = 3

Answer 4

3 x 2^x + 12 = 4 x 9 = 36

3 x 2^x = 36 - 12 = 24

2^x = 24 : 3 = 8 = 2^3

x = 3