Tim x
a) 1/9 * 34 * 3x = 37
b) 1/9 * 27x = 3x
c) 2x+2 - 2x = 96
d) 720 : [ 41 - ( 2x - 5) ] = 23 * 5
Những câu hỏi liên quan
tim x thuoc z
1)26-|x+9|=-13
2)|x+7|-13=25
tim x biet
1)123-3.(x+4)=23
2)720:[41-(2x-5)]=23.5
Tìm x thuoc z:
1) \(26-\left|x+9\right|=-13\)
\(\Leftrightarrow\left|x+9\right|=26-\left(-13\right)\)
\(\Leftrightarrow\left|x+9\right|=39\)
\(\Leftrightarrow\left[{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=39-9=30\\x=-39-9=-48\end{matrix}\right.\)
Vậy: \(x\in\left\{30;-48\right\}\)
2) \(\left|x+7\right|-13=25\)
\(\Leftrightarrow\left|x+7\right|=25+13=38\)
\(\Leftrightarrow x+7\in\left\{38;-38\right\}\)
\(\Leftrightarrow x\in\left\{31;-45\right\}\)
Vậy:.................
tim x biet
\(1)123-3.\left(x+4\right)=23\)
\(\Leftrightarrow3\left(x+4\right)=123-23\)
\(\Leftrightarrow3\left(x+4\right)=100\)
\(\Leftrightarrow x+4=\frac{100}{3}\)
\(\Leftrightarrow x=\frac{100}{3}-4=\frac{100-12}{3}=\frac{88}{3}\)
Vậy:................
2) Tương tự
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29 tháng 11 2021 lúc 7:10
Bài 2 (1,5 điểm): Tìm x
a) 9(x + 28) = 0 b) 720 : [41 – (2x – 5)] = 23.5
9. (x + 28) = 0
x + 28 = 0: 9
x + 28 = 0
x = 0 – 28
x = -28
Vậy x = -28.
720:[41-(2x-5)]=23.5
720:[41-(2x-5)]=8.5
720:[41-(2x-5)]=40
41-(2x-5)=720:40
41-(2x-5)=18
2x-5=41-18
2x-5=23
2x=23+5
2x=28
x=28:2
x=14
Vậy x=14
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b) 720:[41 -(2x-5)]= 8 . 5
720:[41-(2x-5)]=40
[41-(2x-5)]=720 : 40
[41-(2x-5)]=18
2x-5=41-18
2x-5=23
2x=23+5
2x=28
x=28:2
x=14
Vậy x=14
chắc vại ;-;
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2x+23=37:34
[(4x+28).3+55]:5=35
17-(3x+9)=2-(-3+x)
(12x-43).83=4.84
720:[41-(2x-5)]=23.5
128-3.(x+4)=23
(1)\(2x+23=3^7\div3^4\)
\(2x+23=3^3\)
\(2.x=27-23=4\)
\(x=4\div2\)
\(x=2\)
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bai 1 : tinh nhanh :
a) -3/7+ 15/26 - (2/13 - 3/7 ) b) 2.3/7+(2/9-1\(\frac{3}{7}\)) - 5/3 : 1/9 c) -11/23 . 6/7 + 8/7 .-11/23 - 1/23 d) ( 377/231 - 123/89 + 34 /701 ) . ( 1/6 - 1/8 -1 /24)
bai 2 . tim so x biet :
a ) 2/3x - 3/2x = 5/12 b) 2/5 + 3/5 . ( 3x-3,7) = -53/10 c) 7/9:(2+3/4x)+5/9=23/27 d,-2/3.x +1/5=3/10 e, /x/-3/4=5/3
f, /2x-1/3/+5/6=1
5 tháng 6 2021 lúc 9:23
Tìm x ϵ N biết :a) 280 – ( x – 140 ) : 35 270 ; b)( 190 – 2x ) : 35 – 32 16;c) 720 : [ 41 – ( 2x – 5 ) ] 23 .5d) ( x : 23 + 45 ) . 37 – 22 24 . 105 ; e) ( 3x – 4 ) . ( x – 1 ) 3 0 ; f) 22x-1 : 4 83 g) x17 x ; h) ( x – 5 ) 4 ( x – 5 ) 6 ; i) ( x + 2 ) 5 210 ; k ) 1 + 2 + 3 + … + x 78 l) ( 3 .x – 24) . 73 2 .74 ;n) 5x : 52 125 ; m) ( x + 1) 2 ( x + 1) 0 ; o) ( 2 + x ) + ( 4 + x ) + ( 6 + x ) + ……+ ( 52 + x ) 780 ;p) 70⋮ x , 80 ⋮...
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Tìm x ϵ N biết :
a) 280 – ( x – 140 ) : 35 = 270 ;
b)( 190 – 2x ) : 35 – 32 = 16;
c) 720 : [ 41 – ( 2x – 5 ) ] = 23 .5
d) ( x : 23 + 45 ) . 37 – 22 = 24 . 105 ;
e) ( 3x – 4 ) . ( x – 1 ) 3 = 0 ;
f) 22x-1 : 4 = 83
g) x17 = x ;
h) ( x – 5 ) 4 = ( x – 5 ) 6 ;
i) ( x + 2 ) 5 = 210 ;
k ) 1 + 2 + 3 + … + x = 78
l) ( 3 .x – 24) . 73 = 2 .74 ;
n) 5x : 52 = 125 ;
m) ( x + 1) 2 = ( x + 1) 0 ;
o) ( 2 + x ) + ( 4 + x ) + ( 6 + x ) + ……+ ( 52 + x ) = 780 ;
p) 70⋮ x , 80 ⋮ x và x > 8
q) x ⋮ 12 , x ⋮ 25 , x ⋮ 30 và 0 < x < 500
B=x^3+3x^2+3x+1 với x=99
C=x^3-9x^2+27x-26 với x=23
D=(2x-3)^2-(4x-6)(2x-5)+(2x-5) với X= 99
tim x
a, ( 2x - 4 ) ^ 3 = 8
b, 720 / [ 41 - ( 2x - 5 ) ] = 2^3 * 5
(2x - 4)3 = 8
(2x - 4)3 = 23
2x - 4 = 2
2x = 2 + 4
2x = 6
x = 6 : 2
x = 3
\(\frac{720}{41-\left(2x-5\right)}=2^3\times5\)
\(\frac{720}{41-2x+5}=8\times5\)
\(46-2x=\frac{720}{40}\)
\(2x=46-18\)
2x = 28
x = 28 : 2
x = 14
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2 tháng 10 2023 lúc 11:36
giải các phương trình sau:1,sqrt{18x}-6sqrt{dfrac{2x}{9}}3-sqrt{dfrac{x}{2}}2,sqrt{3x}-2sqrt{12x}+dfrac{1}{3}sqrt{27x}-43, 3sqrt{2x}+5sqrt{8x}-20-sqrt{18}04,sqrt{16x+16}-sqrt{9x+9}15,sqrt{4left(1-3xright)}+sqrt{9left(1-3xright)}106,dfrac{2}{3}sqrt{x-3}+dfrac{1}{6}sqrt{x-3}-sqrt{x-3}dfrac{-2}{3}
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giải các phương trình sau:
\(1,\sqrt{18x}-6\sqrt{\dfrac{2x}{9}}=3-\sqrt{\dfrac{x}{2}}\)
\(2,\sqrt{3x}-2\sqrt{12x}+\dfrac{1}{3}\sqrt{27x}=-4\)
3, \(3\sqrt{2x}+5\sqrt{8x}-20-\sqrt{18}=0\)
\(4,\sqrt{16x+16}-\sqrt{9x+9}=1\)
\(5,\sqrt{4\left(1-3x\right)}+\sqrt{9\left(1-3x\right)}=10\)
\(6,\dfrac{2}{3}\sqrt{x-3}+\dfrac{1}{6}\sqrt{x-3}-\sqrt{x-3}=\dfrac{-2}{3}\)
2: ĐKXĐ: x>=0
\(\sqrt{3x}-2\sqrt{12x}+\dfrac{1}{3}\cdot\sqrt{27x}=-4\)
=>\(\sqrt{3x}-2\cdot2\sqrt{3x}+\dfrac{1}{3}\cdot3\sqrt{3x}=-4\)
=>\(\sqrt{3x}-4\sqrt{3x}+\sqrt{3x}=-4\)
=>\(-2\sqrt{3x}=-4\)
=>\(\sqrt{3x}=2\)
=>3x=4
=>\(x=\dfrac{4}{3}\left(nhận\right)\)
3:
ĐKXĐ: x>=0
\(3\sqrt{2x}+5\sqrt{8x}-20-\sqrt{18}=0\)
=>\(3\sqrt{2x}+5\cdot2\sqrt{2x}-20-3\sqrt{2}=0\)
=>\(13\sqrt{2x}=20+3\sqrt{2}\)
=>\(\sqrt{2x}=\dfrac{20+3\sqrt{2}}{13}\)
=>\(2x=\dfrac{418+120\sqrt{2}}{169}\)
=>\(x=\dfrac{209+60\sqrt{2}}{169}\left(nhận\right)\)
4: ĐKXĐ: x>=-1
\(\sqrt{16x+16}-\sqrt{9x+9}=1\)
=>\(4\sqrt{x+1}-3\sqrt{x+1}=1\)
=>\(\sqrt{x+1}=1\)
=>x+1=1
=>x=0(nhận)
5: ĐKXĐ: x<=1/3
\(\sqrt{4\left(1-3x\right)}+\sqrt{9\left(1-3x\right)}=10\)
=>\(2\sqrt{1-3x}+3\sqrt{1-3x}=10\)
=>\(5\sqrt{1-3x}=10\)
=>\(\sqrt{1-3x}=2\)
=>1-3x=4
=>3x=1-4=-3
=>x=-3/3=-1(nhận)
6: ĐKXĐ: x>=3
\(\dfrac{2}{3}\sqrt{x-3}+\dfrac{1}{6}\sqrt{x-3}-\sqrt{x-3}=-\dfrac{2}{3}\)
=>\(\sqrt{x-3}\cdot\left(\dfrac{2}{3}+\dfrac{1}{6}-1\right)=-\dfrac{2}{3}\)
=>\(\sqrt{x-3}\cdot\dfrac{-1}{6}=-\dfrac{2}{3}\)
=>\(\sqrt{x-3}=\dfrac{2}{3}:\dfrac{1}{6}=\dfrac{2}{3}\cdot6=\dfrac{12}{3}=4\)
=>x-3=16
=>x=19(nhận)
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tìm x
a) (x+2)(x+3)-(x-2)(x+5)=6
b) (3x+2)(2x+9)-(x+2)(6x+1)=(x+1)-(x-6)
c) 3(2x-1)(3x-1)-(2x-3)(9x-1)=0
a: Ta có: \(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=6\)
\(\Leftrightarrow x^2+5x+6-x^2-3x+10=6\)
\(\Leftrightarrow2x=-10\)
hay x=-5
b: Ta có: \(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\)
\(\Leftrightarrow6x^2+27x+4x+18-6x^2-x-12x-2=x+1-x+6\)
\(\Leftrightarrow18x+16=7\)
hay \(x=-\dfrac{1}{2}\)
c: Ta có: \(3\left(2x-1\right)\left(3x-1\right)-\left(2x-3\right)\left(9x-1\right)=0\)
\(\Leftrightarrow3\left(6x^2-2x-3x+1\right)-\left(18x^2-2x-27x+3\right)=0\)
\(\Leftrightarrow18x^2-15x+3-18x^2+27x-3=0\)
hay x=0
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xMình cần gấp lắm . giúp xong mình hậu tạ thẻ vt 50k
1) 280-(x-140):35=270
2) (190-2x): 35-32=16
3) 720:[41-(2x-5)]-2.5
4) (x:23+45).37-22=24.105
5) (3x-4).(x-1)=0
6) 2^2x:4=8^3
280 - ( x - 140 ) : 35 = 270
<=> ( x - 140 ) : 35 = 280 -270
<=> ( x -140 ) : 35 = 10
<=> x -140 = 10 . 35
<=> x -140 = 350
<=> x = 350 + 140
<=> x = 490
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1) 280 - ( x - 140 ) : 35 = 270
=> ( x - 140 ) : 35 = 280 - 270 = 10
x - 140 = 350
=> x = 350 + 140
=> x = 390
2) ( 190 - 2x ) : 35 - 32 = 16
190 - 2x = ( 16 + 32 ) . 35 = 1680
x = ( 190 - 1680 ) : 2
x = -745
3) 720 : { 41 - ( 2x - 5 )} -2.5
Sai đề.
4) ( x : 23 + 45 ) . 37 - 22 = 24 .105
x : 23 + 45 = ( 24.105 + 22 ) : 37
x : 23 = 2542/37 - 45 = 877/37
x = 877/37.23 = 20171/37
5) ( 3x - 4 ) ( x - 1 ) = 0
=> 3x - 4 = 0 hoặc x - 1 = 0
3x - 4 = 0 hoặc x - 1 = 0
=> x = 4/3 => x = 1
Vậy x \(\in\) { 4/3;1 }
6) 22x : 4 = 83
=> 22x = 83 . 4 = 2048 = 211
=> 2x = 11
=> x = 11/2
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