Tìm x :
8 x 6 + 288 : ( x - 3 ) mũ 2 = 50
8×6+288:(x—3)^2=50
Tìm x
8.6+288:(x-3)^2=50
48+288:(x-3)^2=50
288:(x-3)^2=50-48
288:(x-3)^2=2
(x-3)^2=288:2
(x-3)^2=144
(x-3)^2=12^2
x-3=12
x=12+3
x=15
Vậy x=15
HT
tìm số tự nhiên x, biết: 8 x 6 + 288 : ( x - 3 )2 = 50
\(8\cdot6+288:\left(x-3\right)^2=50\)
\(48+288:\left(x-3\right)^2=50\)
\(288:\left(x-3\right)^2=50-48=2\)
\(\left(x-3\right)^2=288:2=144\)
Vì x là số tự nhiên nên (x-3) là số tự nhiên.
\(\left(x-3\right)^2=12^2\)
\(x-3=12\)
\(x=12+3=15\)
tìm X , 8 x 6 + 288 : ( X - 3 )=50
8x6+288:(X-3)=50
=>48+288:(X-3)=50
=>288:(X-3)=50-48
=>288:(X-3)=2
=>X-3=288:2
=>X-3=144
=>X=144+3
=>X=147
Trả lời :
8 x 6 + 288 : ( x - 3 ) = 50
48 + 288 : ( x - 3 ) = 50
=> 288 : ( x - 3 ) = 50 - 48
288 : ( x - 3 ) = 2
=> x - 3 = 288 : 2
x - 3 = 144
=> x = 144 + 3
x = 147
Vậy x = 147
8 x 6 + 288 : (x - 3) = 50
=> 48 + 288 : (x - 3) = 50
=> 288 : (x - 3) = 50 - 48
=> 288 : (x - 3) = 2
=> x - 3 = 288 : 2
=> x - 3 = 144
=> x = 144 + 3
=> x = 147
Vậy x = 147
8 . 6 + 288 : ( x - 3)2 =50
\(8.6+288\div\left(x-3\right)^2=50\)
\(\Leftrightarrow\)\(48+288\div\left(x-3\right)^2=50\)
\(\Leftrightarrow\)\(288\div\left(x-3\right)^2=50-48\)
\(\Leftrightarrow\)\(288\div\left(x-3\right)^2=2\)
\(\Leftrightarrow\)\(\left(x-3\right)^2=288\div2\)
\(\Leftrightarrow\)\(\left(x-3\right)^2=144\)
\(\Leftrightarrow\)\(\left(x-3\right)^2=12^2\)
\(\Leftrightarrow\)\(x-3=12\)
\(\Leftrightarrow\)\(x=12+3\)
\(\Leftrightarrow\)\(x=15\)
8×6+288:(x-3)²=50
`8xx6 + 288:(x-3)^2 = 50`
`<=> 48 + 288:(x-3)^2 = 50`
`<=> 288:(x-3)^2 = 50-48`
`<=>288:(x-3)^2 = 2`
`<=>(x-3)^2 = 288:2`
`<=>(x-3)^2 = 144`
`<=>x-3 = 12`
`<=>x = 15`
Vậy `x = 15`
4 mũ n = 4096
5 mũ n = 15625
4 mũ n-1 = 1024
6 mũ n +3 = 216
X mũ 2 = x mũ 3
3 mũ x-1 = 27
3 mũ x+1 = 9
6 mũ x + 1 = 36
3 mũ 2x+1=27
X mũ 50= x
Tìm STN n
a) \(4^n=4096\Rightarrow4^n=4^6\Rightarrow n=6\)
b) \(5^n=15625\Rightarrow5^n=5^6\Rightarrow n=6\)
c) \(6^{n+3}=216\Rightarrow6^{n+3}=6^3\Rightarrow n+3=3\Rightarrow n=0\)
d) \(x^2=x^3\Rightarrow x^3-x^2=0\Rightarrow x^2\left(x-1\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x-1=0\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
e) \(3^{x-1}=27\Rightarrow3^{x-1}=3^3\Rightarrow x-1=3\Rightarrow x=4\)
f) \(3^{x+1}=9\Rightarrow3^{x+1}=3^2\Rightarrow x+1=2\Rightarrow x=1\)
g) \(6^{x+1}=36\Rightarrow6^{x+1}=6^2\Rightarrow x+1=2\Rightarrow x=1\)
h) \(3^{2x+1}=27\Rightarrow3^{2x+1}=3^3\Rightarrow2x+1=3\Rightarrow2x=2\Rightarrow x=1\)
i) \(x^{50}=x\Rightarrow x^{50}-x=0\Rightarrow x\left(x^{49}-1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x^{49}-1=0\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x^{49}=1=1^{49}\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
4n = 4096
4n = 212
n = 12
5n = 15625
5n = 56
n = 6
6n+3 = 216
6n+3 = 23.33
6n+3 = 63
n + 3 = 3
4ⁿ = 4096
4ⁿ = 4⁶
n = 6 (nhận)
Vậy n = 6
--------------------
5ⁿ = 15625
5ⁿ = 5⁶
n = 6 (nhận)
Vậy n = 6
--------------------
4ⁿ⁻¹ = 1024
4ⁿ⁻¹ = 4⁵
n - 1 = 5
n = 6 (nhận)
Vậy n = 6
-------------------
6ⁿ⁺³ = 216
6ⁿ⁺³ = 6³
n + 3 = 3
n = 0 (nhận)
Vậy n = 0
--------------------
x² = x³
x³ - x² = 0
x(x² - 1) = 0
x = 0 (nhận) hoặc x² - 1 = 0
*) x² - 1 = 0
x² = 1
x = 1 (nhận) hoặc x = -1 (loại)
Vậy x = 0; x = 1
--------------------
3ˣ⁻¹ = 27
3ˣ⁻¹ = 3³
x - 1 = 3
x = 3 + 1
x = 4 (nhận)
Vậy x = 4
---------------------
3ˣ⁺¹ = 9
3ˣ⁺¹ = 3²
x + 1 = 2
x = 2 - 1
x = 1 (nhận)
Vậy x = 1
--------------------
6ˣ⁺¹ = 36
6ˣ⁺¹ = 6²
x + 1 = 2
x = 2 - 1
x = 1 (nhận)
Vậy x = 1
--------------------
3²ˣ⁺¹ = 27
3²ˣ⁺¹ = 3³
2x + 1 = 3
2x = 3 - 1
2x = 2
x = 1 (nhận)
Vậy x = 1
--------------------
x⁵⁰ = x
x⁵⁰ - x = 0
x(x⁴⁹ - 1) = 0
x = 0 (nhận) hoặc x⁴⁹ - 1 = 0
*) x⁴⁹ - 1 = 0
x⁴⁹ = 1
x = 1 (nhận)
Vậy x = 0; x = 1
1. 6 X mũ 3 -8 =40
2. 4 X mũ 5 +15=47
3. 2 X mũ 3-4=12
4. 5 X mũ 3-5=0
5. (X -5) mũ 2016 = (X-5) mũ 2018
6. (3X -2) mũ 20= (3X-1) mũ 20
7. (3X -1) mũ 10 = (3X-1) mũ 20
8. (2X -1) mũ 50 = 2X-1
9. (X phần 3 -5) mũ 2000= ( X phần 3-5) mũ 2008
1. \(6x^3-8=40\\ 6x^3=48\\ x^3=8\\ \Rightarrow x=2\)Vậy x = 2
2. \(4x^5+15=47\\ 4x^5=32\\ x^5=8\\ \Rightarrow x\in\varnothing\left(\text{vì }x\in N\right)\)Vậy x ∈ ∅
3. \(2x^3-4=12\\ 2x^3=16\\ x^3=8\\ \Rightarrow x=2\)Vậy x = 2
4. \(5x^3-5=0\\ 5x^3=5\\ x^3=1\\ \Rightarrow x=1\)Vậy x = 1
5. \(\left(x-5\right)^{2016}=\left(x-5\right)^{2018}\\ \Rightarrow\left[{}\begin{matrix}x-5=0\\x-5=1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=5\\x=6\end{matrix}\right.\)Vậy \(x\in\left\{5;6\right\}\)
6. \(\left(3x-2\right)^{20}=\left(3x-1\right)^{20}\\ \Rightarrow3x-2=3x-1\\ 3x-3x=2-1\\ 0=1\left(\text{vô lí}\right)\)Vậy x ∈ ∅
7. \(\left(3x-1\right)^{10}=\left(3x-1\right)^{20}\\ \left(3x-1\right)^{10}=\left[\left(3x-1\right)^2\right]^{10}\\ \Rightarrow\left(3x-1\right)^2=3x-1\\ \left(3x-1\right)^2-\left(3x-1\right)=0\\ \left(3x-1\right)\left[\left(3x-1\right)-1\right]=0\\ \left(3x-1\right)\left(3x-2\right)=0\\ \Rightarrow\left[{}\begin{matrix}3x-1=0\\3x-2=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}3x=1\\3x=2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{1}{3}\left(\text{loại vì }x\in N\right)\\x=\frac{2}{3}\left(\text{loại vì }x\in N\right)\end{matrix}\right.\)Vậy x ∈ ∅
8. \(\left(2x-1\right)^{50}=2x-1\\ \left(2x-1\right)^{50}-\left(2x-1\right)=0\\ \left(2x-1\right)\left[\left(2x-1\right)^{49}-1\right]=0\\ \Rightarrow\left[{}\begin{matrix}2x-1=0\\\left(2x-1\right)^{49}=1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=1\\2x-1=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\frac{1}{2}\left(\text{loại vì }x\in N\right)\\x=1\left(t/m\right)\end{matrix}\right.\)Vậy x = 1
9. \(\left(\frac{x}{3}-5\right)^{2000}=\left(\frac{x}{3}-5\right)^{2008}\\ \left(\frac{x}{3}-5\right)^{2008}-\left(\frac{x}{3}-5\right)^{2000}=0\\ \left(\frac{x}{3}-5\right)^{2000}\left[\left(\frac{x}{3}-5\right)^8-1\right]=0\\ \Rightarrow\left[{}\begin{matrix}\left(\frac{x}{3}-5\right)^{2000}=0\\\left(\frac{x}{3}-5\right)^8=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}\frac{x}{3}-5=0\\\frac{x}{3}-5=1\\\frac{x}{3}-5=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}\frac{x}{3}=5\\\frac{x}{3}=6\\\frac{x}{3}=4\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=5\cdot3=15\\x=6\cdot3=18\\x=4\cdot3=12\end{matrix}\right.\)Vậy \(x\in\left\{15;18;12\right\}\)
\(1.6x^3-8=40\\ \Leftrightarrow6x^3=48\\ \Leftrightarrow x^3=8\Leftrightarrow x^3=2^3=\left(-2\right)^3\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)
Vậy \(x\in\left\{2;-2\right\}\)
\(2.4x^3+15=47\) (T nghĩ đề là mũ 3)
\(\Leftrightarrow4x^3=32\Leftrightarrow x^3=8=2^3=\left(-2\right)^3\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)
Vậy \(x\in\left\{2;-2\right\}\)
Câu 3, 4 tương tự nhé.
\(5.\left(x-5\right)^{2016}=\left(x-5\right)^{2018}\\ \Leftrightarrow\left(x-5\right)^{2018}-\left(x-5\right)^{2016}=0\\ \Leftrightarrow\left(x-5\right)^{2016}\left[\left(x-5\right)^2-1\right]=0\\ \Leftrightarrow\left(x-5\right)^{2016}\left(x-5-1\right)\left(x-5+1\right)=0\\ \Leftrightarrow\left(x-5\right)^{2016}\left(x-6\right)\left(x-4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}\left(x-5\right)^{2016}=0\\x-6=0\\x-4=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x-5=0\\x=6\\x=4\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=5\\x=6\\x=4\end{matrix}\right.\)
Vậy \(x\in\left\{4;5;6\right\}\)
3 . 2 mũ x + 2 mũ x +1 + 2 mũ x+2 = 288
\(3.2^x+2^{x+1}+2^{x+2}=288\\ \Leftrightarrow2^x\left(3+2+2^2\right)=288\\ \Leftrightarrow2^x=32=2^5\\ \Leftrightarrow x=5\)
tik mik nha
Ta có: \(3\cdot2^x+2^{x+1}+2^{x+2}=288\)
\(\Leftrightarrow2^x\cdot\left(3+2+4\right)=288\)
\(\Leftrightarrow2^x=32\)
hay x=5
tính
a,8.6+288:(x-)^2=50
b,{x^2-[6^2-(8^2-9.7)^3-7.5]^3-5.3)^3=1^3
a,8.6+288:(x-3)^2=50
48+288:(x-3)^2=50
288:(x-3)^2=2
(x-3^2=288:2
(x-3)^2=144=12^2
x=12+3
=>x=15
x=100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000