Tìm x biết \(\frac{3^2.3^8}{27^3}=3^x\)
\(\frac{3^2.3^8}{27^3}=3^x\)
Tìm x
\(\frac{3^2.3^8}{27^3}=3^x\)
\(\Leftrightarrow\frac{3^{2+8}}{\left(3^3\right)^3}=3^x\)
\(\Leftrightarrow\frac{3^{10}}{3^9}=3^x\)
\(\Leftrightarrow3=3^x\)
\(\Leftrightarrow x=1\)
\(\frac{3^2.3^8}{27^3}=3^x\)
<=> \(\frac{3^{10}}{3^9}=3^x\)
<=> \(3=3^x\)
<=> x=1
\(\frac{3^2\cdot3^8}{27^3}=3^x\)
\(\Leftrightarrow3^2\cdot3^8=27^3\cdot3^x\)
\(\Leftrightarrow3^{10}=\left(3^3\right)^3\cdot3^x\)
\(\Leftrightarrow3^{10}=3^9\cdot3^x\)
\(\Leftrightarrow3^{10}=3^{9+x}\)
\(\Rightarrow10=9+x\)
\(\Leftrightarrow x=1\)
\(\frac{3^2.3^8}{27^3}=3^x\)
Ta có :\(\frac{3^2.3^8}{27^3}=3^x\)
\(\Rightarrow\frac{3^{10}}{\left(3^3\right)^3}=3^x\)
\(\Rightarrow\frac{3^{10}}{3^9}=3^x\)
\(\Rightarrow3^1=3^x\)
\(\Rightarrow x=1\)
Vậy \(x=1\)
\(\frac{3^2.3^8}{27^3}\)=\(\frac{3^{10}}{27^3}\)=\(\frac{3^{10}}{\left(3^3\right)^3}\)=\(\frac{3^{10}}{3^9}\)=3
Mà \(\frac{3^2.3^8}{27^3}\)=3x
\(\Rightarrow\)3=3x
\(\Rightarrow\)x=1
Vậy x=1.
Tìm x, biết:
3x.5=278+2.310
\(\frac{3^2.3^8}{27^3}\)=\(^{3^x}\)
\(\frac{3^2.3^8}{37^3}=3^x\)
\(\Rightarrow\frac{3^{10}}{\left(3^3\right)^3}=3^x\Rightarrow\frac{3^{10}}{3^9}=3^x\Rightarrow3^1=3^x\Rightarrow x=1\)
Tìm số nguyên x, nếu biết:
1)\(4.3^{x-1}+2.3^{x+2}=4.3^6+2.3^9\)
2)\(\frac{5}{3}.8^{x+2}-\frac{3}{5}.8^x=\frac{5}{3}.8^{11}-\frac{3}{5}.8^9\)
3)\(\left(\frac{1}{3}+\frac{1}{6}\right).2^{x+4}-2^x=2^{13}-2^{10}\)
Mấy bn giúp mk nha!!! lm câu nào cg đc hết á, cảm ơn nha!!!!!
:D
a) \(\Leftrightarrow2.\left(\frac{2.3^x}{3}+3^x.3^2\right)=2.3^6\left(2+3^3\right)\)
\(\Leftrightarrow2.\left(\frac{2.3^x+3.3^x.3^2}{3}\right)=2.3^6.29\)
\(\Leftrightarrow2.\left[\frac{3^x.\left(2+3.3^2\right)}{3}\right]=2.3^6.19\)
\(\Leftrightarrow2.3^{x-1}.29=2.3^6.29\Leftrightarrow3^{x-1}.29=\frac{2.3^6.29}{2}=3^6.29\Leftrightarrow3^{x-1}=\frac{3^6.29}{29}=3^6\)
\(\Leftrightarrow3^{x-1}=3^6\Leftrightarrow x-1=6\Leftrightarrow x=6+1=7\)
vậy x=7 . Chọn mình nha
mấy bài sao tương tự nếu ko biết thì nhắn tin mình chỉ típ nha
Bài 1 : Tìm x, y biết :
a. 10x : 5y = 20y
b. 2x = 4y-1 và 27y = 3x+8
Bài 2 :Chứng minh rằng \(\frac{3}{1^2.2^2}+\frac{5}{2^2.3^2}+\frac{7}{3^2.4^2}+...+\frac{19}{9^2.10^2}< 1\)
a)
\(\text{( 25 – 2x )³ : 5 – 3^2 = 4^2}\)
\(\text{( 25 – 2x )³ : 5 – 9 = 16}\)
\(\text{( 25 – 2x )³ : 5 = 16 + 9}\)
\(\text{( 25 – 2x )³ : 5 = 25}\)
\(\text{( 25 – 2x )³ = 25 . 5}\)
\(\text{( 25 – 2x )³ = 125}\)
\(\text{( 25 – 2x )³ = 5³}\)
\(\text{25 – 2x = 5}\)
\(\text{2x = 25 – 5}\)
\(\text{2x = 20}\)
\(\text{x = 10}\)
\(\text{________________________________________}\)
b)
\(\text{2.3^x = 10.3^12 + 8.27^4}\)
\(\text{2.3^x = 10.3^12 + 8.(3^3)^4}\)
\(\text{2.3^x = 3^12 . (10+8)}\)
\(\text{2.3^x = 3^12 . 18}\)
\(\text{3^x = 3^12 . 18:2}\)
\(\text{3^x = 3^12 . 9}\)
\(\text{3^x = 3^12 . 3^2}\)
\(\text{3^x = 3^14}\)
\(\text{=> x=14}\)
Tìm x, biết :
a) x15 = x
b) 2.3x = 10 . 312 + 8 . 27
c) (7x - 11)3 = 25 . 52 + 200
Mọi người giúp mình bài tìm x
1) (x-2/9)^3 = (8/27)^2
2)2.3^x -405 = 3^x-1
3)4/3 : 0,8 = 0,75x : (-1,5)