Câu hỏi của NZFuzion TM

Question

2 mũ x + 2 mũ x+3= 144

2 mũ x-1 + 5.2 mũ x-2= 224

Minh Nguyễn Cao · Accepted Answer

a) $2^x+2^{x+3}=144$

$2^x\left(1+2^3\right)=144$

$2^x.9=144$

$2^x=144:9=16$

=> $2^x=2^4\Rightarrow x=4$

b) $2^{x-1}+5.2^{x-2}=224$

$2^{x-2}\left(2+5\right)=224$

$2^{x-2}.7=224\Rightarrow2^{x-2}=32\Rightarrow2^{x-2}=2^5$

=> x - 2 = 5 => x = 7

Câu trả lời:

a) $2^x+2^{x+3}=144$

$2^x\left(1+2^3\right)=144$

$2^x.9=144$

$2^x=144:9=16$

=> $2^x=2^4\Rightarrow x=4$

b) $2^{x-1}+5.2^{x-2}=224$

$2^{x-2}\left(2+5\right)=224$

$2^{x-2}.7=224\Rightarrow2^{x-2}=32\Rightarrow2^{x-2}=2^5$

=> x - 2 = 5 => x = 7

Sắc màu · Answer

a ) 2^x + 2^{x + 3} = 144
=> 2^x . ( 1 + 2³ ) = 144

=> 2^x . 9 = 144

=> 2^x = 16

=> 2^x= 2⁴

=> x = 4
Vậy x = 4

b ) 2^{x - 1} + 5. 2^{x - 2} = 224

=> 2^{x - 2} . ( 2 + 5 ) = 224

=> 2^{x - 2} . 7 = 224

=> 2^{x - 2} = 32

=> 2^{x - 2} = 2⁵

=> x - 2 = 5

=> x = 7

Vậy x = 7