a) \(2x+5=20-\left(12-7\right)\)
\(2x+5=20-5\)
\(2x+5=15\)
\(2x=15-5\)
\(2x=10\)
\(x=10:2\)
\(x=5\)
Vậy \(x=5\)
b) \(\left|x\right|=\left|-5\right|\)
\(\Rightarrow\left|x\right|=5\)
\(\Rightarrow x=\pm5\)
Vậy \(x\in\left\{5;-5\right\}\)
a) \(2x+5=20-\left(12-7\right)\)
\(2x+5=20-5\)
\(2x+5=15\)
\(2x=15-5\)
\(2x=10\)
\(x=10:2\)
\(x=5\)
Vậy \(x=5\)
b) \(\left|x\right|=\left|-5\right|\)
\(\Rightarrow\left|x\right|=5\)
\(\Rightarrow x=\pm5\)
Vậy \(x\in\left\{5;-5\right\}\)
b) 1500.(x – 7) = 0
c) (2.x – 4).(48 – 12.x) = 0
d) (x + 12).(x – 1) =0
Bài 2: Tìm x biết:
a) 128- 3(x+ 4) = 23
b) [(14x+ 26). 3+ 55]: 5= 35
d) 720: [41- (2x- 5)]= 23. 5
tìm x , biết
a) 5/6 - x = -7 / 12 + 2/3
b) ( 2,4x - 36 ) : 1va5/7 = -1
c) 2 ( x - 1 ) - 3 ( 2x + 2 ) - 4 ( 2x + 3 ) = 16
d ) ( x - 2 ) . ( x + 3 ) > 0
Tìm x , biết:
a)2x - 1 = 7
b) 3(x+5) = 21
c) 20 - (3x - 1) = 15
d) (x - 135) - 120 = 0
tìm x
a)-5.(-x+7)-3.(-x-5)=-4.(12-x)+48
b) (-x-7)-5.(-x-3)=12.(3-x)
c)-2.(15-3x)-4.(7x+8)=-5-9.(-2x+1)
d) (-3x-7) - 4.(-2x-11)=7.(4x+10)+9
Tìm x biết :
a) ( x-1):3=23
b) 12-2(x+5)=-10
c) x-12(x+5)=-10
d) 6-| x| =5
e) 13-x:2=10
f) | 12 -x | -7=5
i) x2 -7=2
k) x3 -4 =-12
m) 7\(⋮\) (x - 3 )
n) 3 \(⋮\) ( 2x+1)
1,(x-20).(2y+1)=17
2,(x-10.(y+20)=7
3,x.y-3=12
4,x.y+x+2y=5
5,x.y+2x+2y=16
Bài 1: Tìm x, biết:
a, 2/1/4x - 9/1/4 = |-20|
b, 1/2x + 2/3. ( x-2) =1/3
c, x- 25% = 6/11. (1/2+ 3/4 - 1/3)
d, - (-23) + (-36) - |-57| + (-29) .2
e, x/30 = 3/10 + -1/15
f, (x - 1/4) : 4/5 = 15/16
g, 1/3/5- 7/12 :x - -9/4
h, (2/4/5. x +50 ). 2/3 = -51
tìm xez , biết
a) |x - 3 | - 7 = 13
b) 72 - 3 . | x + 1 | = 9
c) 17 - ( 43 - |x| ) = 45
d) 3 | x - 1 | - 5 = 7
e) -12 ( x - 5 ) + 7 (3 - x ) = 5
Tìm x biết
a,(3x-1).1/2x+5=0
b,-5.(x+1/5)-1/2.(x+3/5)=-x+1/5
c,2|1/2x-1/3|-3/2=1/4
d,|20/9-x|=1/12+1/20+1/30+1/42+1/56+1/72
e,1/2.3.x+1/3.4.x+1/4.5.x+...+1/49.50.x=1
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