a/ => x³ = 64 => x³ = 4³ => x = 4

b/ => x⁵ = 32 => x⁵ = 2⁵ => x = 2 

c/ => 3^x = 81 => 3^x = 3⁴ => x = 4

d/ => 3^x+2 = 243 => 3^x+2 = 3⁵ => x + 2 = 5 => x = 3

e/ => (x - 2)³ = 64 => (x - 2)³ = 4³ => x - 2 = 4 => x = 6

f/ => (x - 8)² = 81 => (x - 8)² = 9² => x - 8 = 9 => x = 17

b) \(3.2^{x+1}=12\)

\(2^{x+1}=12:3\)

\(2^{x+1}=4\)

\(2^{x+1}=2^2\)

\(x+1=2\)

\(x=2-1\)

\(x=1\)

Vậy \(x=1\)

c) \(2^{x-1}=2^3+2^4-2^3\)

\(2^{x-1}=8+16-8\)

\(2^{x-1}=16\)

\(2^{x-1}=2^4\)

\(x-1=4\)

\(x=5\)

Vậy \(x=5\)

d) \(x^{50}=x\)

\(x^{50}-x=0\)

\(\Rightarrow x\in\left\{0;1\right\}\)

Vậy \(x\in\left\{0;1\right\}\)

\(b.3.2^{x+1}=12\\ \Rightarrow2^{x+1}=4\\ \Rightarrow2^{x+1}=2^2\\ \Rightarrow x=1\\ \)

c) \(2^{x-1}=2^3-2^3+2^4\\ \Rightarrow2^{x-1}=0+16\\ \Rightarrow2^{x-1}=16\\ \Rightarrow2^{x-1}=2^4\\ \Rightarrow x-1=4\\ \Rightarrow x=5\)

d) \(x^{50}=x\\ \Rightarrow x=0;1\)

e) \(2\left(2x-1\right)^4=32\\ \Rightarrow\left(2x-1\right)^4=16\\ \Rightarrow\left(2x-1\right)^4=2^4\\ \Rightarrow2x-1=2\\ \Rightarrow2x=3\\ \Rightarrow x=\frac{3}{2}\)

g) Bí 

1, 4\(^{x+1}\) + 4\(^0\) = 65

\(\Rightarrow\)4\(^{x+1}\) = 65 - 1

\(\Rightarrow\)x + 1      = 64 : 4

\(\Rightarrow\)x + 1      =  16

\(\Rightarrow\)x = 15

2) 10 + 2x = 16\(^{^2}\): 4\(^3\)

\(\Rightarrow\)10 + 2x = 4

\(\Rightarrow\)2x = 4 - 10

\(\Rightarrow\)2x = -6

\(\Rightarrow\)x = -3

Bài 1:

Tao có:

\(81^7mod\left(405\right)\)

\(81^3\equiv81mod\left(405\right)\)

\(81^6\equiv81^2\equiv81mod\left(405\right)\)

\(81^7\equiv81^2.81\equiv81mod\left(405\right)\)

Ta có:

\(27^9mod\left(405\right)\)

\(27^3\equiv243mod\left(405\right)\)

\(27^9\equiv243^3\equiv162mod\left(405\right)\)

Ta có:

\(9^{13}mod\left(405\right)\)

\(9\equiv9mod\left(405\right)\)

\(9^3\equiv324mod\left(405\right)\)

\(9^9\equiv324^3\equiv324mod\left(405\right)\)

\(9^{10}\equiv324.9\equiv81mod\left(405\right)\)

\(9^{13}\equiv81.324\equiv324mod\left(405\right)\)

\(81^7+27^9-9^{13}:405=81+162-324:405=-0,2\)

\(\Rightarrow81^7+27^9-9^{13}⋮405\left(đpcm\right)\)

Casio không biết có áp dụng ntn vào bài này được không nữa? Nhưng mình ôn hổm rày thấy có bài gần giống vậy, nên mình làm thử bạn tham khảo nha chúc bạn học tốt! ^^

a,3^x+1 +3^x+3^x-1=30.(3⁴)³

3^x+1+3^x+3^x-1=20726199

3^x.3+3^x.1+3^x:3=20726199

3^x.3+3^x.1+3^x.\(\frac{1}{3}\)=20726199

3^x(3+1+\(\frac{1}{3}\))=20726199

3^x.\(\frac{13}{3}\)=20726199

3^x=20726199:\(\frac{13}{3}\)

3^x=4782969

3^x=3¹⁴

Vậy x:=14

Câu trả lời bài 1 ý a làm kiểu gì

oc cho