![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
5.x - 9 = 5 + 3.x
5x - 3x = 5 + 9
2x = 14
x = 14 : 2
x = 7
--------------------
(5x + 1)² = 36/49
5x + 1 = 6/7 hoặc 5x + 1 = -6/7
*) 5x + 1 = 6/7
5x = 6/7 - 1
5x = -1/7
x = -1/7 : 5
x = -1/35
*) 5x + 1 = -6/7
5x = -6/7 - 1
5x = -13/7
x = -13/7 : 5
x = -13/35
Vậy x = -13/35; x = -1/35
--------------------
2ˣ⁻¹ = 16
2ˣ⁻¹ = 2⁴
x - 1 = 4
x = 4 + 1
x = 5
![](https://rs.olm.vn/images/avt/0.png?1311)
(5x+1)2 =\(\frac{36}{49}\)
(5x+1)2=\(\frac{6}{7}^2\)
=>(5x+1)=\(\frac{6}{7}\)
5x =\(\frac{6}{7}\)-1=\(\frac{-1}{7}\)
x = \(\frac{-1}{7}\) :5
x= \(\frac{-1}{35}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) (5x+1)2=36/49
=> (5x+1)2=(6/7)2=(-6/7)2
+) 5x+1=6/7
=> 5x=6/7-1
=> 5x=-1/7
=> x=-1/7:5
=> x=-1/35
+) 5x+1=-6/7
=> 5x=-6/7-1
=> 5x=-13/7
=> x=-13/7:5
=> x=-13/35
Vậy \(x\in\left\{-\frac{13}{35};\frac{-1}{35}\right\}\).
b) đã làm.
c) | x-5 | = x-3
+) x-5=x-3
=> x-x-5+3=0
=> 0-2=0
=> -2=0 (vô lí, loại)
+) x-5=-(x-3)
=> x-5=-x+3
=> x+x-5-3=0
=> 2x-8=0
=> 2x=8
=> x=4
Vậy x=4.
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{a}{1}=\dfrac{b}{2}=\dfrac{c}{3}=\dfrac{4a-3b+2c}{4-6+6}=\dfrac{36}{4}=9\\ \Rightarrow\left\{{}\begin{matrix}a=9\\b=18\\c=27\end{matrix}\right.\\ \dfrac{x}{2}=\dfrac{y}{3};\dfrac{y}{5}=\dfrac{z}{4}\Rightarrow\dfrac{x}{10}=\dfrac{y}{15}=\dfrac{z}{16}=\dfrac{x-y+z}{10-15+16}=\dfrac{-49}{11}\\ \Rightarrow\left\{{}\begin{matrix}x=-\dfrac{490}{11}\\y=-\dfrac{735}{11}\\z=-\dfrac{784}{11}\end{matrix}\right.\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a, 5^x . (5^3)^2=625
5^x . 5^6=5^4
5^x=5^4:5^6
5^x=5^-2
=> x=-2
đáp án là x=27/7
\(\left(x-3\right)^2=\frac{36}{49}\)
=> \(\left(x-3\right)^2=\left(\frac{6}{7}\right)^2\)
=> \(x-3=\frac{6}{7}\)
=> \(x=\frac{6}{7}+3\)
=> \(x=\frac{27}{7}\)