Question

[Ngọc Vũ]

Bài 1: Tìm x là STN biết:

1/ 5^{x - 2} - 3² = 2⁴ - ( 6⁸ : 6⁶ - 6²)

2/ 3^x + 4² = 19⁶ : (19³ x 19²) - 3.1²⁰¹⁴

3/ 2^x + 2^{x + 4} = 272

4/ 3 + 2^{x - 1} = 24 - \([4^2-(2^2-1)]\)

Answer 1

[Nguyễn Lê Phước Thịnh]

1: =>\(5^{x-2}-9=2^4-\left(6^2-6^2\right)\)

=>\(5^{x-2}=16+9=25\)

=>x-2=2

=>x=4

2: \(\Leftrightarrow3^x+16=19^6:19^5-3=19-3=16\)

=>3^x=0

=>x=0

3: \(\Leftrightarrow2^x+2^x\cdot16=272\)

=>2^x*17=272

=>2^x=16

=>x=4

4: \(\Leftrightarrow2^{x-1}+3=24-\left(4^2-2^2+1\right)=24-\left(16-4+1\right)\)

=>\(2^{x-1}+3=24-16+4-1=8+4-1=12-1=11\)

=>2^x-1=8

=>x-1=3

=>x=4