3^x+3.2^x-6^x=24
tìm x biết 8.3^x+3.2^x-6^x=24
\(8.3^x+3.2^x-6^x=24\)
\(\Rightarrow8.3^x+3.2^x-6^x-24=0\)
\(\Rightarrow\left(8.3^x-2^x.3^x\right)-\left(24-3.2^x\right)=0\)
\(\Rightarrow3^x\left(8-2^x\right)-3\left(8-2^x\right)=0\Rightarrow\left(8-2^x\right)\left(3^x-3\right)=0\)
\(\Rightarrow\orbr{\begin{cases}2^x=8\\3^x=3\end{cases}\Rightarrow}\orbr{\begin{cases}x=3\\x=1\end{cases}}\)
Tìm x biết
10 + 2 . x = 4⁵ : 4³
2 x - 6² : 18 = 3.2²
70 - 5 . ( x- 3 ) = 3.2
\(10+2\cdot x=4^5:4^3\)
\(\Rightarrow10+2\cdot x=4^{5-3}\)
\(\Rightarrow10+2\cdot x=4^2\)
\(\Rightarrow10+2\cdot x=16\)
\(\Rightarrow2\cdot x=16-10\)
\(\Rightarrow2\cdot x=6\)
\(\Rightarrow x=\dfrac{6}{2}=3\)
__________________
\(2\cdot x-6^2:18=3\cdot2^2\)
\(\Rightarrow2\cdot x-36:18=12\)
\(\Rightarrow2\cdot x-2=12\)
\(\Rightarrow2\cdot x=12+2\)
\(\Rightarrow2\cdot x=14\)
\(\Rightarrow x=\dfrac{14}{2}=7\)
_________________
\(70-5\cdot\left(x-3\right)=3\cdot2\)
\(\Rightarrow70-5\cdot\left(x-3\right)=6\)
\(\Rightarrow70-5x+15=6\)
\(\Rightarrow-5x+15=6-70\)
\(\Rightarrow-5x+15=64\)
\(\Rightarrow-5x=64-15\)
\(\Rightarrow-5x=49\)
\(\Rightarrow x=-\dfrac{49}{5}\)
\(2^{x-1}+2^{x+1}-3.2^{x-1}=24\)
\(3^x+3^{x+1}-3^{x-1}=90\)
Tìm x ; n thuộc N biết
a) \(x^2.x.x=6^{12}.6^6\)
b) \(3.2^n=24\)
c) \(4.\left(2.n\right)=16\)
d) \(3^{x+1}-2^0=3^2+15^2\)
c,4.(2.n) = 16
suy ra n= 2
4.( 2.2 ) = 16
1/3 .2x+5/3.2x+2=1/2 . 26 + 2 . 613
(1/3 - 1/6 ) . 2x + 2x+1=212+210
5/3 .8x+2-3/5 . 8x = 5/3 . 811 -3/5.83
Chứng minh
Chứng minh ( 245x5424x210) chia hết 7263
Chứng minh (54-53)3/125 = 64/125
Tìm x
a) 197 -9 ( x+3) =80
b) 7 (x- 14) + 35 = 56
c) 2.3x+1 =54
d) 3.2x-1 =24
a)197-9(x+3)=80
=>9(x+3)=197-80
=>9(x+3)=117
=>x+3=117:9
=>x+3=13
=>x=13-3=10
b)7(x-14)+35=56
=>7(x+14)=56-35
=>7(x+14)=21
=>x+14=21/7
=>x+14=3
=>x=3-14=(-11)
c)2.3x-1=54
=>3x-1=54:2
=>3x-1=27
=>3x-1=33
=>x-1=3
=>x=3+1=4
d)3.2x-1=24
=>2x-1=24:3
=>2x-1=8
=>2x-1=23
=>x-1=3
=>x=3+1=4
\(a,197-9\left(x+3\right)=80\)
\(197-\left(9x+27\right)=80\)
\(197-9x-27=80\)
\(197-9x=107\)
\(9x=90\)
\(x=10\)
\(b,7\left(x-141\right)+35=56\)
\(7x-987+35=56\)
\(7x=56-35+987\)
\(7x=1008\)
\(x=144\)
197 - 9 . ( x + 3 ) = 80
9 . ( x + 3 ) = 197 - 80
9 . ( x + 3 ) = 117
x + 3 = 117 : 9
x + 3 = 13
x = 13 - 3
x = 10
7 . ( x - 14 ) + 35 = 56
7 . ( x - 14 ) = 56 - 35
7 . ( x - 14 ) = 21
x - 14 = 21 : 7
x - 14 = 3
x = 3 + 14
x = 17
1) 5.2²+ (x+3)=5² 6) 4³ - (x-2)=5²
2) 2³+(x-3²)= 5³-4³ 7) 3⁴+ (x+5)=5.3²
3) 3.2 + (x+5²)=10² 8) 2³.5 - (x+ 3²)=10
4) 2⁶+(5+x)= 3⁴ 9) 3³ - (x+2⁴)=7
5) 5+(x + 3³)= 2⁶ 10) 7² - (15+x)=5.2²
1; 5.22 + (\(x\) + 3) = 52
5.4 + (\(x\) + 3) = 25
20 + (\(x\) + 3) = 25
\(x\) + 3 = 25 - 20
\(x+3\) = 5
\(x\) = 5 - 3
\(x\) = 2
Vậy \(x=2\)
2; 23 + (\(x\) - 32) = 53 - 43
8 + (\(x\) - 9) = 125 - 64
8 + (\(x\) - 9) = 61
\(x\) - 9 = 61 - 8
\(x\) - 9 = 53
\(x\) = 53 + 9
\(x\) = 62
Vậy \(x\) = 62
3; 3.2 + (\(x\) + 52) = 102
6 + (\(x\) + 25) = 100
\(x\) + 25 = 100 - 6
\(x\) + 25 = 94
\(x\) = 94 - 25
\(x\) = 69
Vậy \(x\) = 69
6x+2+6x=1332
2.3x+1-3x=135
3x(3.2-1)=5
2.3x+1-3x=135
Khó quá
\(\frac{3!\left(2^x\left(15\%\left(-8\frac{2\frac{2}{5}}{5}+8\frac{3\frac{3}{4}}{5}\right)\right)\right)}{24}=\frac{81}{x^3.2}\)
x = ?
a) \(3^x:3^2=243\)
\(3^{x-2}=3^5\)
=> x - 2 = 5
=> x = 7
b) \(6.2^x+3.2^x=2^x.\left(6+3\right)=2^x.9=9.29=261\)
=> 2x = 9
=> x không tồn tại vì 2 khi nâng lên lũy thừa ra số chẵn.
c) d) tương tự