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x.232 = 811
x.232 = (23)11
x.232 = 233
x = 233:232
x = 2
2x+1:8 = 325
2x+1 = 325.8
2x+1 = (25)5.23
2x+1 = 225.23
2x+1 = 228
=> x + 1 = 28
=> x = 28 - 1 = 27
x.232 = 811
x .232 =(23 )11
x.232 = 233
x = 233 : 232
x = 2
2x+1:8=325
2x+1=325 x 8
2x+1= ( 25 )5 x 23
2x+1 = 225 x 23
2x+1 = 228
x + 1 = 28
x = 28 - 1
x = 27
![](https://rs.olm.vn/images/avt/0.png?1311)
a, 3 x + 1 : 3 4 = 81
3 x - 3 = 3 4
x – 3 = 4
x = 7
Vậy x = 7
b, 3 x + 3 . 3 x + 1 = 729
3 2 x + 4 = 3 6
2x + 4 = 6
x = 1
Vậy x = 1
c, 2 x + 3 . 2 x = 128
2 2 x + 3 = 2 7
2x + 3 = 7
x = 2
Vậy x = 2
d, 23 + 3 x = 5 6 : 5 3
23 + 3 x = 5 3
23 + 3x = 125
3x = 102
x = 34
Vậy x = 34
e, 2 x + 2 x + 4 = 272
2 x + 2 x . 2 4 = 272
2 x ( 1 + 2 4 ) = 272
2 x . 17 = 272
2 x = 16
2 x = 2 4
x = 4
Vậy x = 4
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-1/2=x-1/6
x-1/6=-1/2
x =-1/2+1/6
x =-3/6+1/6
x =-2/6=-1/3
nhớ ks cho mình nhé
những bài toán nâng cao lớp 6 hả bạn
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1) Ta có: \(\dfrac{3x+7}{11}=\dfrac{5x-7}{9}\)
\(\Leftrightarrow9\left(3x+7\right)=11\left(5x-7\right)\)
\(\Leftrightarrow27x+63=55x-77\)
\(\Leftrightarrow27x-55x=-77-63\)
\(\Leftrightarrow-28x=-140\)
hay x=5
Vậy: S={5}
![](https://rs.olm.vn/images/avt/0.png?1311)
Lời giải:
a) \((5x-1)^6=729=3^6=(-3)^6\)
\(\Rightarrow \left[\begin{matrix} 5x-1=3\\ 5x-1=-3\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{4}{5}\\ x=\frac{-2}{5}\end{matrix}\right.\)
b)
\(\frac{8}{25}=\frac{2^x}{5^{x-1}}=\frac{2^x}{5^x:5}=5.(\frac{2}{5})^x\)
\(\Rightarrow \frac{8}{125}=(\frac{2}{5})^x\)
\(\Rightarrow (\frac{2}{5})^3=(\frac{2}{5})^x\Rightarrow x=3\)
c)
\((\frac{1}{16})^x=(\frac{1}{2})^{10}\)
\(\Rightarrow (\frac{1}{2^4})^x=(\frac{1}{2})^{10}\)
\(\Rightarrow (\frac{1}{2})^{4x}=(\frac{1}{2})^{10}\Rightarrow 4x=10\Rightarrow x=\frac{5}{2}\)
d)
\(9^{x}:3^x=3\Rightarrow (\frac{9}{3})^x=3\)
\(\Rightarrow 3^x=3^1\Rightarrow x=1\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a)\(\dfrac{1}{3}^x=\dfrac{1}{729}\)
\(\dfrac{1}{3}^x=\dfrac{1}{3}^6\)
Suy ra x=6
vậy x=6
b)\(\left(\dfrac{1}{3}-\dfrac{1}{2}\right)^x=\dfrac{1}{36}\)
\(\left(-\dfrac{1}{6}\right)^x\)=\(\dfrac{1}{6}^2\)
Do đó x=2
Vậy x=2
c)\(\dfrac{25}{5}^x=\dfrac{1}{125}\)
\(5^x=5^{-3}\)
Suy ra x=-3
Vậy x=-3
d)\(7^{2n-\dfrac{1}{49}}=-343\)
\(-7^{2n-\dfrac{1}{49}}=-7^3\)
Do đó \(2n-\dfrac{1}{49}=3\)
2n=\(\dfrac{148}{49}\)
n=\(\dfrac{74}{49}\)
vậy n=\(\dfrac{74}{49}\)
chúc bạn học tốt ạ
![](https://rs.olm.vn/images/avt/0.png?1311)
a) -3x+4+5x=-10-x
-3x+4+5x+10+x=0
(-3x+5x+x)+10=0
3x+10=0
3x=-10
x=\(\dfrac{-10}{3}\)
Vậy x=\(\dfrac{-10}{3}\)
b)-x+1=-3x-8
-x+1+3x+8=0
(-x+3x)+(1+8)=0
2x+9=0
2x=-9
x=\(\dfrac{-9}{2}\)
Vậy x=\(\dfrac{-9}{2}\)
c)8-(x-1)=10+(x+5)
8-x+1=10+x+5
9-x=15+x
9-x-15-x=0
(9-15)-(x+x)=0
-6-2x=0
2x=-6
x=-3
Vậy x=-3
d)100+(x+7)-(-2x+3)=8+(x+100)
100+x+7+2x-3=8+x+100
(x+2x)+(100+7-3)=(8+100)+x
3x+104=108+x
3x+104-108-x=0
(3x-x)+(104-108)=0
2x-4=0
2x=4
x=2
Vậy x=2
e, \(\left|2x+5\right|=\left|x-1\right|\)
\(\Rightarrow\left\{{}\begin{matrix}2x+5=1-x\\2x+5=x-1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}3x=-4\\x=-6\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=-\dfrac{4}{3}\\x=-6\end{matrix}\right.\)
g, \(\left|-x+4\right|=\left|-3x-8\right|\)
\(\Rightarrow\left\{{}\begin{matrix}-x+4=3x+8\\-x+4=-3x-8\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}-4x=4\\2x=-12\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=-1\\x=-6\end{matrix}\right.\)
h, \(\left|x+4\right|=\left|-3-8\right|\)
\(\Rightarrow\left|x+4\right|=\left|-11\right|=11\)
\(\Rightarrow\left\{{}\begin{matrix}x+4=-11\\x+4=11\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=-15\\x=7\end{matrix}\right.\)
Chúc bạn học tốt!!!
b)
<=> (x-1)[(x-1)^7-1]=0
<=>x=1 (TH1)
Và (x-1)^7=1 (TH2)
<=> x-1=1
<=>x=2.
Vậy x=1 hoặc 2.
c) <=>3^x= 9
<=> x=2.
d) <=> 25^x=5^24:5
<=> 25^x=5^23
<=> (5^x)^2=5^23 ???