l x-7l+13=25 =
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)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) |-8 - 17| - |-13| = 25 - 13 = 12
b) (23 - 49) + (13 + 49)
= 23 - 49 + 13 + 49
= (23 + 13) + (-49 + 49)
= 36 + 0 = 36
c) |-13 - 7| - |-13 + 7|
= 20 - 6 = 14
d) -(18- 73) + (18 - 73 + 28)
= -18 + 73 + 18 - 73 + 28
= (-18 + 18) + (73 - 73) + 28
= 0 + .0 + 28 = 28
![](https://rs.olm.vn/images/avt/0.png?1311)
d, \(\left(3x-2^4\right).7^3=2.7^4\)
\(\Rightarrow3x-2^4=2.7^4:7^3\)
\(\Rightarrow3x-16=2.7\\ \Rightarrow3x=14+16\\ \Rightarrow3x=30\Rightarrow x=10\)
Vậy.....
e, \(x-\left[42+\left(-28\right)\right]=-8\)
\(\Rightarrow x-14=-8\\ \Rightarrow x=6\)
Vậy.....
g, \(x-7=-5\)
\(\Rightarrow x=-5+7\Rightarrow x=2\)
Vậy.....
h, \(15-5\left(x+4\right)=-12-3\)
\(\Rightarrow15-5x-20=-15\)
\(\Rightarrow-5x=-15-15+20\)
\(\Rightarrow-5x=-10\Rightarrow x=2\)
Vậy.....
Chúc bạn học tốt!!!
d/ \(\left(3x-2^4\right)\cdot7^3=2\cdot7^4\)
\(\Rightarrow3x-16=\dfrac{2\cdot7^4}{7^3}=14\)
\(\Rightarrow3x=14+16=30\)
\(\Rightarrow x=\dfrac{30}{3}=10\)
e/ Đễ ==> tự lm thì tốt hơn nhé
g/ Đễ ==> tự lm thì tốt hơn nhé
h/ \(15-5\left(x+4\right)=-12-3\)
\(\Rightarrow15-5x-20=-15\)
\(\Rightarrow-5x=-15+20-15=-10\)
\(\Rightarrow x=\dfrac{-10}{-5}=2\)
i/ \(\left(7-x\right)-\left(25+7\right)=-25\)
\(\Rightarrow7-x-25-7=-25\)
\(\Rightarrow-x=-25-7+7+25\)
\(\Rightarrow-x=0\Rightarrow x=0\)
k/ \(\left|x+2\right|=0\Rightarrow x+2=0\Rightarrow x=-2\)
l/ \(\left|x-3\right|=7-\left(-2\right)\)
\(\Rightarrow\left|x-3\right|=9\)
\(\Rightarrow\left[{}\begin{matrix}x-3=9\\x-3=-9\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=12\\x=-6\end{matrix}\right.\)
m/ \(\left|x-5\right|=\left|-7\right|\Rightarrow\left|x-5\right|=7\)
\(\Rightarrow\left[{}\begin{matrix}x-5=7\\x-5=-7\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=12\\x=-2\end{matrix}\right.\)
![](https://rs.olm.vn/images/avt/0.png?1311)
|x + 7| = |x + 9|
=> x + 7 = x + 9 hoặc x + 7 + x + 9 = 0
=> 7 = 9 (vô lí) hoặc 2x = -16
=> x = -8
vậy x = -8
Ta có \(|x+7|=|x+9|\Rightarrow\orbr{\begin{cases}x+7=x+9\\x+7=-x-9\end{cases}\Rightarrow\orbr{\begin{cases}x-x=9-7\\x+x=-9-7\end{cases}\Rightarrow\orbr{\begin{cases}0x=2\\2x=-16\end{cases}}}}\)
suy ra 2x=-16 suy ra x=-8
Vậy x=-8
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
lx-7l-13=21
=> lx-7l=21+13
=> lx-7l=33
=> x-7= 33 hoặc x-7= -33
+) x-7= 33 => x = 33+7 = 40
+) x-7= -33 => x = - 33+7 = -26
Vậy x = 40 hặc x = -26
![](https://rs.olm.vn/images/avt/0.png?1311)
/4-x/=/-7/
/4-x/=7
Xét 2 trường hợp
TH1: 4-x=7
x=-3
TH2: 4-X=-7
x=11
KL: X E {-3;11}
![](https://rs.olm.vn/images/avt/0.png?1311)
l x + 2 l = 0
=>x + 2 =0
=>x=0-2=-2
l x - 3 l = 7 - (-2)
l x - 3 l = 9
th1: x - 3 =9
=>x=9+3=12
th2:x - 3 =-9
=>x=-9+3=-6
l x - 5 l = l-7l
=>l x - 5 l = 7
th1: x - 5 = 7
=>x=7+5=12
th2 x-5=-7
=>x=-7+5=-2
\(\left|x+2\right|=0\Rightarrow x=-2\)
\(\left|x-3\right|=7-(-2)\)
\(\Rightarrow\left|x-3\right|=7+2\)
\(\Rightarrow\hept{\begin{cases}x-3=9\\x-3=-9\end{cases}\Rightarrow}\hept{\begin{cases}x=12\\x=-6\end{cases}}\)
\(\left|x-5\right|=\left|-7\right|\)
\(\Rightarrow\hept{\begin{cases}x-5=-7\\x-5=7\end{cases}\Rightarrow}\hept{\begin{cases}x=-2\\x=12\end{cases}}\)
\(\text{Chúc bạn học tốt }:)\)
l x-7l+13=25
<=> |x-7|= 25-13
<=>|x-7|= 12
=>x-7 = 12 hoặc x-7= -12
<=> x=12+7 hoặc x= -12+7
<=> x= 19 hoặc x= -5
Vậy x = 19 hoặc x= -5