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A , 3 - ( 17 - x ) = 289 - ( 36 + 289 )
3 - 17 + x = 0 - 36
-14 + x = -36
x = -36 - ( - 14 ) = -22
B, 25 - ( x + 5 ) = -415 - ( 15 - 415 )
25 - x - 5 = 0 - 15
20 - x = -15
x = 20 - ( - 15 ) = 35
C , 34 + ( 21 - x ) = ( 3747 - 30 ) - 3746
34 + 21 - x = 1 - 30
55 - x = -29
x = 55 - (-29 ) = 74
D , -2x - ( x -17 ) = 34 - ( -x + 25 )
- 2x - x + 17 = 34 - 25 + x
- 3x + 17 = 9 + x
- 3x - x = 9 - 17
-4x = -8
x = -8 : ( - 4 )
x = 2
E , 17x + ( -16x - 37 ) = x + 43
17x - 16x -37 = x + 43
x - 37 = x + 43
-37 - 43 = x - x
- 80 = 0 ( vô lý )
G , ( x + 12 ) . (x - 3 ) = 0
\(\hept{\begin{cases}x+12=0\\x-3=0\end{cases}}\)
\(\hept{\begin{cases}x=-12\\x=3\end{cases}}\)
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a) 3x-17=x+3
3x-x=17+3
2x=20 =>x=10
b) |x-3|-12=|-5|
|x-3|=17
x-3=17 hoặc x-3=-17
nếu x-3=17 thì x=20
nếu x-3=-17 thì x=-14
c) 2,5-(x-5)=-415-(15-415)
2,5-(x-5)=-15
x-5=2,5+15
x-5=17,5 =>x=22,5
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1) \(3x-17=x+3\)
\(3x-x=3+17\)
\(2x=20\)
\(x=10\)
Vậy x=10
2) \(\left|x-3\right|-12=\left|-5\right|\)
\(\left|x-3\right|-12=5\)
\(\left|x-3\right|=17\)
\(\Rightarrow x-3=17\) hoặc \(x-3=-17\)
\(\Rightarrow x=20\) hoặc \(x=-14\)
Vậy x= 20 hoặc x= -14
3) \(25-\left(x-5\right)=-415-\left(15-415\right)\)
\(25-\left(x-5\right)=-15\)
\(-\left(x-5\right)=-15-25\)
\(-\left(x-5\right)=-40\)
\(x-5=40\)
\(x=35\)
Vậy x=35
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1,
a) |x| + |y + 1| =0
Ta có: |x| \(\ge\) 0 (Với x \(\in\) Z)
|y + 1| \(\ge\) 0 (Với y\(\in\) Z)
\(\Rightarrow\) |x| + |y + 1| \(\ge\) 0
Dấu "=" xảy ra (=):
\(\left\{\begin{matrix}\left|x\right|=0\\\left|y+1\right|=0\end{matrix}\right.\Rightarrow\left\{\begin{matrix}x=0\\y+1=0\end{matrix}\right.\Rightarrow}\left\{\begin{matrix}x=0\\y=0-1\end{matrix}\right.\Rightarrow}\left\{\begin{matrix}x=0\\y=-1\end{matrix}\right.\)
Vậy x = 0; y = -1
b) (2 - x)4 = 81
\(\Rightarrow\) (2 - x)4 = 34 = (-3)4
\(\Rightarrow\) \(\left[\begin{matrix}2-x=3\\2-x=-3\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=2-3\\x=2-\left(-3\right)\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=-1\\x=5\end{matrix}\right.\)
Vậy: x \(\in\) {-1; 5}
c) |x - 1| + (-3) = 17
\(\Rightarrow\) |x - 1| = 17 - (-3)
\(\Rightarrow\) |x - 1| = 20
\(\Rightarrow\left[\begin{matrix}x-1=-20\\x-1=20\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=-20+1\\x=20+1\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=-19\\x=21\end{matrix}\right.\)
Vậy: x \(\in\) {-19; 21}
d) 3 - (17 - x) = 289 - (36 + 289)
\(\Rightarrow\) 3 - (17 - x) = 289 - 36 - 289
\(\Rightarrow\) 3 - (17 - x) = 289 - 289 - 36\(\Rightarrow\) 3 - (17 - x) = 0 - 36
\(\Rightarrow\) 3 - (17 - x) = -36 \(\Rightarrow\) 17 - x = 3 - (-36) \(\Rightarrow\) 17 - x = 39 \(\Rightarrow\) x = 17 - 39 \(\Rightarrow\) x = -22 Vậy: x = -22 e) 25 - (x + 5) = -415 - (15 - 415) \(\Rightarrow\) 25 - (x + 5) = -415 - 15 + 415 \(\Rightarrow\) 25 - (x + 5) = (-415 + 415) - 15 \(\Rightarrow\) 25 - (x + 5) = 0 - 15 \(\Rightarrow\) 25 - (x + 5) = -15 \(\Rightarrow\) x + 5 = 25 - (-15) \(\Rightarrow\) x + 5 = 40 \(\Rightarrow\) x = 40 -5 \(\Rightarrow\) x = 35 Vậy: x = 35 f) 34 + (21 - x) = (3747 - 30) - 3746 \(\Rightarrow\) 34 + (21 - x) = 3747 - 30 - 3746 \(\Rightarrow\) 34 + (21 - x) = 3747 - 3746 - 30 \(\Rightarrow\) 34 + (21 - x) = 1 - 30 \(\Rightarrow\) 34 + (21 - x) = -29 \(\Rightarrow\) 21 - x = -29 - 34 \(\Rightarrow\) 21 - x = -63 \(\Rightarrow\) x = 21 - (-63) \(\Rightarrow\) x = 84 Vậy: x = 84![](https://rs.olm.vn/images/avt/0.png?1311)
a. 3x-17=x+3=>3x-17-x+3=0=>2x-14=0=>2x=14=>x=7
mấy bài sau giải dễ lắm, áp dụng nhân từng thừa số nếu bạn chưa học lập phương trình, bạn cứ làm toán nhân như vậy nhé! chúc bạn học giỏi!!!
a) 3x - 17 = x + 3
<=> 3x - x = 17 + 3
<=> 2x = 20
<=> x = 10
Vậy x = 10
b) (x-3) - 12 = (-5)
<=> x - 3 = 7
<=> x = 10
Vậy x = 10
c)25 - (x - 5) = -415 - (15-415)
<=> 25 - (x - 5) = -15
<=> x - 5 = 40
<=> x = 45
Vậy x = 45
d) 2x - 15 = -47
<=> 2x = -32
<=> x = -16
Vậy x = -16
e) (-5)2 - (5x - 3) = 43
<=> 5x - 3 = -18
<=> 5x = -15
<=> x = -3
Vậy x = -3
g)(x - 3) (2x + 6) = 0
\(\orbr{\begin{cases}x-3=0\\2x+6=0\end{cases}}\)
\(\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)
Vậy x \(\in\){ 3; -3 }
Học tốt nhá :))
1. 3x - 17 = x+3
3x - x = 3 + 17
2x = 20
x = 20 :2
x = 10
2. |x-3| - 12 = |-5|
|x-3| -12 = 5
|x-3| = 5 + 12
|x-3| = 17
=> x-3 = +17 , -17
x = 17 + 3
x = 20
x = -17 + 3
x = -14
3 . 25 - ( x -5 ) = -415 -( 15 -415)
25 - x +5 = -415 - 15 +415
25 - x +5 = ( -415 + 415) -15
25 - x +5 = 0-5 = -5
25 - x = -5-5
25 - x = -10
x = 25 - -10
x = 35
4. ( x -3 ) . ( 2x +6 ) = 0
=> x-3 = 0 hoặc 2x +6 = 0
x = 0 + 3 = 3
2x = 0-6=-6
x = -6 : 2
x = -3
\(1;3x-17=x+3\)
\(\Leftrightarrow3x-x=3+17\)
\(\Leftrightarrow2x=20\)
\(\Rightarrow x=10\)
\(2;\left|x-3\right|-12=\left|-5\right|\)
\(\Leftrightarrow\left|x-3\right|-12=5\)
\(\Leftrightarrow\left|x-3\right|=5+12\)
\(\Leftrightarrow\left|x-3\right|=17\)
\(\Rightarrow\orbr{\begin{cases}x-3=17\\3-x=17\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=17+3\\-x=17-3\end{cases}\Leftrightarrow\orbr{\begin{cases}x=20\\x=-14\end{cases}}}\)
\(3;25-\left(x-5\right)=-415-\left(15-415\right)\)
\(\Leftrightarrow25-x+5=-415-15+415\)
\(\Leftrightarrow-x=-415-15+415-25-5\)
\(\Leftrightarrow-x=-45\)
\(\Rightarrow x=45\)
\(4;\left(x-3\right)\left(2x+6\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-3=0\\2x+6=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=3\\x=-3\end{cases}}}\)