Question

Giúp mình câu 23;24;25;26

Answer 1

23.2^x+2-2^x+1=32

2^x.2²-2^x.2=32

2^x.(2²-2¹)=32

2^x.2=32

2^x=32:2

2^x=16

⇒x=4

24.3^x+5+3^x+2=756

3^x.3⁵+3^x.3²=756

3^x.(3⁵+3²)=756

3^x.252=756

3^x=756:252

3^x=3

⇒x=1

 

Answer 2

26.(2/3)^x.(2/3)²+(2/3)^x.(2/3)=20/27

(2/3)^x.[(2/3)²+(2/3)]=20/27

(2/3)^x.10/9=20/27

(2/3)^x=20/27:10/9

(2/3)^x=2/3

⇒x=1