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|2x-3|=5 suy ra:th1:2x-3=5 2x=5+3 2x=8 x=8:2 x=4 th2:2x-3=-5 2x=-5+3 x=-2 x=-2:2 x=-1
1.
a) | 2x+3 |= 5
=>2x+3=\(\pm\) 5
=>\(\left[\begin{array}{nghiempt}2x+3=5\\2x+3=-5\end{array}\right.\) => \(\left[\begin{array}{nghiempt}2x=2\\2x=-8\end{array}\right.\) => \(\left[\begin{array}{nghiempt}x=1\\x=-4\end{array}\right.\)
Vậy x\(\in\)\(\left\{1;-4\right\}\)
a) Ta có: \(\left|2x-1\right|=\left|2x+3\right|\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-1=2x+3\left(loại\right)\\2x-1=-2x-3\end{matrix}\right.\Leftrightarrow2x+2x=-3+1\)
\(\Leftrightarrow4x=-2\)
hay \(x=-\dfrac{1}{2}\)
\(|5x-3|-x=7\)
\(|5x-3|=7+x\)
\(\orbr{\begin{cases}5x-3=7+x\\5x-3=-7-x\end{cases}}\)
\(\orbr{\begin{cases}5x-x=7+3\\5x+x=-7+3\end{cases}}\)
\(\orbr{\begin{cases}4x=10\\6x=-4\end{cases}}\)
\(\orbr{\begin{cases}x=2,5\\x=\frac{-2}{3}\end{cases}}\)
Vậy x = 2,5 hoặc x = -2/3
Hi Hi!
Noob ơi, bạn phải đưa vào máy tính ý solve cái là ra x luôn, chỉ tội là đợi hơi lâu
a, 4.(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)
=> 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84
=> (72 + 84) + (-20x - 36x) = (30x - 6x) + (-240 - 84)
=> 156 - 56x = 24x - 324
=> 24x + 56x = 324 + 156
=> 80x = 480
=> x = 480 : 80 = 6
Vậy x = 6
a) \(\left|2x-3\right|=5\)
⇒ \(\left[{}\begin{matrix}2x-3=5\\2x-3=-5\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}2x=5+3=8\\2x=\left(-5\right)+3=-2\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}x=8:2\\x=\left(-2\right):2\end{matrix}\right.\)
⇒ \(\left[{}\begin{matrix}x=4\\x=-1\end{matrix}\right.\)
Vậy \(x\in\left\{4;-1\right\}.\)
b) Đề sai rồi, bạn xem lại nhé.
c) \(\left|x-1\right|+3x=11\)
⇒ \(\left|x-1\right|=11-3x\)
+) Với \(x\ge1\)
⇒ \(x-1=11-3x\)
⇒ \(x+3x=11+1\)
⇒ \(4x=12\)
⇒ \(x=12:4\)
⇒ \(x=3.\)
+) Với \(x< 1\)
⇒ \(1-x=11-3x\)
⇒ \(1-11=\left(-3x\right)+x\)
⇒ \(-10=-2x\)
⇒ \(x=\left(-10\right):\left(-2\right)\)
⇒ \(x=5.\)
Vậy \(x\in\left\{3;5\right\}.\)
Chúc bạn học tốt!
a) |2x - 3| = 5
2x - 3 = 5 Hoặc 2x - 3 = -5
* 2x - 3 = 5
2x = 5 + 3
2x = 8
x = 8 : 2
x = 4
2x - 3 = -5
2x = -5 + 3
2x = -2
x = -2 : 2
x = -1
Vậy x ϵ {-2; -1}
\(a,\Rightarrow\left[{}\begin{matrix}2x-3=5\\3-2x=5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4\\x=-1\end{matrix}\right.\\ b,\Rightarrow\left|x-1\right|=1-3x\\ \Rightarrow\left[{}\begin{matrix}x-1=1-3x\\x-1=3x-1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=0\end{matrix}\right.\)
a) \(\Rightarrow\left[{}\begin{matrix}2x-3=5\\2x-3=-5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=8\\2x=-2\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=4\\x=-1\end{matrix}\right.\)
b) \(\left|x-1\right|+3x=1\left(đk:x\le\dfrac{1}{3}\right)\)
\(\Rightarrow x-1=3x-1\)
\(\Rightarrow2x=0\Rightarrow x=0\left(tm\right)\)
a) \(\left|2x-3\right|=5\)
\(\Leftrightarrow\orbr{\begin{cases}2x-3=5\\2x-3=-5\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x=8\\2x=-2\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=4\\x=-1\end{cases}}\)
Vậy : \(x\in\left\{4,-1\right\}\)
b) \(\left|2x-1\right|=\left|2x-3\right|\)
\(\Leftrightarrow\orbr{\begin{cases}2x-1=2x-3\\2x-1=3-2x\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x-2x=-3+1\\2x+2x=3+1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}0=-2\\4x=4\end{cases}}\)
\(\Rightarrow x=1\)
Vậy : \(x=1\)
c) \(\left|x-1\right|+3x=11\)
\(\Leftrightarrow\left|x-1\right|=11-3x\)
\(\Leftrightarrow\orbr{\begin{cases}x-1=11-3x\\x-1=3x-11\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x+3x=11+1\\3x-x=-1+11\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x=12\\2x=10\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=3\\x=5\end{cases}}\)
Vậy : \(x\in\left\{3,5\right\}\)
d) \(\left|5x-3\right|-x=7\)
\(\Leftrightarrow\left|5x-3\right|=7+x\)
\(\Leftrightarrow\orbr{\begin{cases}5x-3=7+x\\5x-3=-7-x\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}5x-x=7+3\\5x+x=-7+3\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x=10\\6x=-4\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{10}{4}=\frac{5}{2}\\x=-\frac{4}{6}=-\frac{2}{3}\end{cases}}\)
Vậy : \(x\in\left\{\frac{5}{2},-\frac{2}{3}\right\}\)
a,\(|2x-3|=5\)
\(\Rightarrow2x-3=5\)hoặc\(2x-3=-5\)
\(2x=5+3\)hoặc\(2x=-5+3\)
\(2x=8\)hoặc\(2x=-2\)
\(\Rightarrow x=\frac{8}{2}=4\)hoặc\(x=-\frac{2}{2}=-1\)
Vậy.......
b,Sai vế phải r bn ơi
c,\(|x-1|+3x=11\)
\(|x-1|=11-3x\)
\(\Rightarrow x-1=+\left(11-3x\right)\)hoặc\(\Rightarrow x-1=-\left(11-3x\right)\)
\(x-1=11-3x\)hoặc\(x-1=-11+3x\)
\(x+3x=11+1\)hoặc\(x-3x=-11+1\)
\(4x=12\)hoặc\(-2x=-10\)
\(\Rightarrow x=\frac{12}{4}=3\)hoặc\(x=\frac{-10}{-2}=5\)
Vậy.....
d,\(|5x-3|-x=7\)
\(|5x-3|=7+x\)
\(\Rightarrow5x-3=+\left(7+x\right)\)hoặc\(5x-3=-\left(7+x\right)\)
\(5x-3=7+x\)hoặc\(5x-3=-7-x\)
\(5x-x=7+3\)hoặc\(5x+x=-7+3\)
\(4x=10\)hoặc\(6x=-4\)
\(\Rightarrow x=\frac{10}{4}=2,5\)hoặc\(x=-\frac{4}{6}=-\frac{2}{3}\)
Vậy......
a) \(\left|3x-1\right|=5\)
\(\Rightarrow\orbr{\begin{cases}3x-1=5\\3x-1=-5\end{cases}}\Rightarrow\orbr{\begin{cases}3x=6\\3x=-4\end{cases}}\Rightarrow\orbr{\begin{cases}x=2\\x=\frac{-4}{3}\end{cases}}\)
b) \(\left|x-1\right|+11=45\)
\(\Rightarrow\left|x-1\right|=35\)
\(\Rightarrow\orbr{\begin{cases}x-1=35\\x-1=-35\end{cases}\Rightarrow\orbr{\begin{cases}x=36\\x=-34\end{cases}}}\)
c)\(\left|2x+1\right|=\left|2x-3\right|\)
\(\Rightarrow\orbr{\begin{cases}2x+1=2x-3\\2x+1=-2x+3\end{cases}\Rightarrow\orbr{\begin{cases}2x-2x=-3-1\\2x+2x=3-1\end{cases}\Rightarrow}\orbr{\begin{cases}0=-4\\4x=2\end{cases}\Rightarrow}\orbr{\begin{cases}vôlis\\x=\frac{1}{2}\end{cases}}}\)
d)\(\left|x+1\right|-5x=7\)
\(\Rightarrow\left|x+1\right|=7+5x\)
\(\Rightarrow\orbr{\begin{cases}x+1=7+5x\\x+1=-7-5x\end{cases}\Rightarrow\orbr{\begin{cases}x-5x=7-1\\x+5x=-7-1\end{cases}\Rightarrow}\orbr{\begin{cases}-4x=6\\6x=-8\end{cases}\Rightarrow}\orbr{\begin{cases}x=-\frac{3}{2}\\x=-\frac{4}{3}\end{cases}}}\)
hok tốt!!!
| 3x - 1 | = 5
=> 3x - 1 = 5 hoặc 3x - 1 = -5
th 1 :
3x - 1 = 5
3x = 5 + 1
3x = 6
=> x = 2
th 2 :
3x - 1 = -5
3x = - 5 + 1
3x =-4
=> x = -4/3
vậy x = 2 ; x = -4/3