Tìm x :
3 . ( x + 6 ) = x - 8
Tìm x :
a/ 6 x ( X + 9845 ) = 29042 x 6
b/ ( X : 3 ) x 8 = 8 x 3
Giúp tuiiiiiii
a)
`6xx(x+9845)=29042xx6`
`6xx(x+9845)=174252`
`x+9845=174252:6`
`x+9845=29042`
`x=29042-9845`
`x=19197`
b)
`(x:3)xx8=8xx3`
`(x:3)xx8=24`
`x:3=24:8`
`x:3=3`
`x=3xx3`
`x=9
Lời giải:
a.
$6\times (x+9845)=29042\times 6$
$x+9845=29042\times 6:6=29042$
$x=29042-9845=19197$
b.
$(x:3)\times 8=8\times 3$
$(x:3)=8\times 3:8=3$
$x=3\times 3=9$
a) 6 x ( X + 9845 ) = 29042 X 6
6 x ( X + 9845 ) = 174252
X + 9845 = 174252 : 6
X + 9845 = 29042
X = 29042 - 9845
X = 19197
Vay x = 19197
b) (X : 3) x 8 = 8 x 3
( X : 3) x 8 = 24
X : 3 = 24 : 8
X : 3 = 3
X = 3 x 3
X = 9
Vay X = 9
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15
1: x=3/4-1/2=3/4-2/4=1/4
2: x-1/5=2/11
=>x=2/11+1/5=21/55
3: x-5/6=16/42-8/56
=>x-5/6=8/21-4/28=5/21
=>x=5/21+5/6=15/14
4: x/5=5/6-19/30
=>x/5=25/30-19/30=6/30=1/5
=>x=1
5: =>|x|=1/3+1/4=7/12
=>x=7/12 hoặc x=-7/12
6: x=-1/2+3/4
=>x=3/4-1/2=1/4
11: x-(-6/12)=9/48
=>x+1/2=3/16
=>x=3/16-1/2=-5/16
1)x= 1/4
2)x= 2/11+ 1/5
x= 21/55
3)x - 5/6 = 5/21
x = 5/21+5/6
x = 15/14
4)x/5 = 5/6 + -19/30
x:5 = 1/5
x = 1/5.5
x = 1
5) |x| - 1/4 = 6/18
|x| = 6/18 - 1/4
|x| =7/12
⇒x= 7/12 hoặc -7/12
6)x = -1/2 +3/4
x= 1/4
7) x/15 = 3/5 + -2/3
x:15 = -1/15
x = -1/15. 15
x = -1
8)11/8 + 13/6 = 85/x
85/24 = 85/x
⇒ x = 24
9) x - 7/8 = 13/12
x = 13/12 + 7/8
x = 47/24
10)x - -6/15 = 4/27
x = 4/27 + (-6/15)
x = -34/135
11) -(-6/12)+x = 9/48
x= 9/48 - 6/12
x = -5/16
12) x - 4/6 = 5/25 + -7/15
x -4/6 = -4/15
x = -4/15 + 4/6
x = 2/5
Tìm x, biết:
a) (x - 8.25).4 = 0;
b) (x - 50): 4 - 3 = 97;
c) 8.(22 -x) = 8;
d) (x : 3-3)(x: 6-6) = 0.
a) x = 200
b) x = 450
c) x = 21
d) x = 9 hoặc x = 36
Tìm x biết:
a) 6* 8^x-1 + 8^x+1 = 6* 8^19 + 8^21
b) 4* 3^x-1 + 2* 3^x+2 = 4* 3^6 +2* 3^9
a) \(6.8^{x-1}+8^{x+1}=6.8^{19}+8^{21}\)
\(\Rightarrow x-1+x+1=19+21\)
\(=2x=40\)
\(\Rightarrow x=20\)
b) \(4.3^{x-1}+2.3^{x+2}=4.3^6+2.3^9\)
\(\Rightarrow x-1+x+2=6+9\)
\(\Rightarrow2x+1=15\)
\(\Rightarrow2x=14\)
\(\Rightarrow x=7\)
Tìm số nguyên x , biết: a) x+21=6 B) x-10=-8 c) (-8)x=(-7).(-6)-2. d) 20+8.(x+3)=5².4
\(a,x+21=6\\ \Rightarrow x=-15\\ b,x-10=-8\\ \Rightarrow x=2\\ c,\left(-8\right)x=\left(-7\right)\left(-6\right)\\ \Rightarrow\left(-8\right)x=42\\ \Rightarrow x=-4\\ d,20+8\left(x+3\right)=5^2.4\\ \Rightarrow20+8\left(x+3\right)=25.4\\ \Rightarrow20+8\left(x+3\right)=100\\ \Rightarrow8\left(x+3\right)=80\\ \Rightarrow x+3=10\\ \Rightarrow x=7\)
\(a.x+21=6\\ x=6-21\\ x=-15\\ b.x-10=-8\\ x=-8+10\\ x=2\\ c.-8x=-7.\left(-6\right)-2\\ -8x=42-2\\ -8x=40\\ x=40:\left(-8\right)\\ x=-5\)
\(d.20+8\left(x+3\right)=5^2.4\\ 20+8x+24=25.4\\ 44+8x=100\\ 8x=100-44\\ 8x=56\\ x=56:8\\ x=7\)
a)x+21=6 b)x-10=-8
X=6-21 x=-8+10
X=-15 x=2
C)(-8).x=-7×(-6)-2 d)20+8.(x+3)=5^2.4
(-8).x=40 20+8.(x+3)=100
X=40÷8 8.(x+3)=100-20
X=5 8.(x+3)=80
X+3=80÷8
X+3=10
X=10-3=7
tìm x (5x + 3^4) x 6^8 = 6^9 x 3^4
(5x + 3⁴).6⁸ = 6⁹.3⁴
5x + 3⁴ = 6⁹.3⁴ : 6⁸
5x + 81 = 6.81
5x = 6.81 - 81
5x = 81.(6 - 1)
5x = 81.5
x = 81.5 : 5
x = 81
Tìm x:
x×3=6
2×x=8
x×3=21
- x×3=6
x=6:3
x=2
- 2×x=8
x=8:2
x=4
- x×3=21
x=21:3
x=7
Tìm x
a. x - 3/4 = 6 x 3/8
b.7/8 : x = 3 1/2
c.x + 1/2 x 1/3 = 3/4
a) \(x-\dfrac{3}{4}=6.\dfrac{3}{8}=\dfrac{9}{4}\)
\(\Rightarrow x=\dfrac{9}{4}+\dfrac{3}{4}=3\)
c) \(x+\dfrac{1}{2}.\dfrac{1}{3}=\dfrac{3}{4}\)
\(\Rightarrow x+\dfrac{1}{6}=\dfrac{3}{4}\Rightarrow x=\dfrac{3}{4}-\dfrac{1}{6}=\dfrac{9}{12}-\dfrac{2}{12}=\dfrac{7}{12}\)
Bạn xem lại đề c
b) \(\dfrac{7}{8}:x=3\dfrac{1}{2}\)
\(\Rightarrow\dfrac{7}{8}:x=\dfrac{7}{2}\)
\(\Rightarrow x=\dfrac{7}{8}:\dfrac{7}{2}\)
\(\Rightarrow x=\dfrac{1}{4}\)
Tìm x:
a) (x - 5)(x + 3) = x(x - 3)
b) (x + 2)2 = (x - 1)(x + 2)
c) (x - 6)(x + 6) = x2
d) (2x - 3)2 = 4x2 - 8
a: Ta có: \(\left(x-5\right)\left(x+3\right)=x\left(x-3\right)\)
\(\Leftrightarrow x^2-2x-15-x^2+3x=0\)
\(\Leftrightarrow x=15\)
b: Ta có: \(\left(x+2\right)^2=\left(x-1\right)\left(x+2\right)\)
\(\Leftrightarrow x+2=0\)
hay x=-2
c: Ta có: \(\left(x-6\right)\left(x+6\right)=x^2\)
\(\Leftrightarrow x^2-36=x^2\)(vô lý)
a. (x - 5)(x + 3) = x(x - 3)
<=> x2 + 3x - 5x - 15 = x2 - 3x
<=> x2 - x2 + 3x - 5x + 3x - 15 = 0
<=> x = 15
b. (x + 2)2 = (x - 1)(x + 2)
<=> x2 + 4x + 4 = x2 + 2x - x - 2
<=> x2 - x2 + 4x - 2x + x = -2 - 4
<=> 3x = -5
<=> \(x=\dfrac{-5}{3}\)
c. (x - 6)(x + 6) = x2
<=> x2 - 36 - x2 = 0
<=> x2 - x2 = 36
<=> 0 = 36 (vô lí)
Vậy nghiệm của PT là \(S=\varnothing\)
d. (2x - 3)2 = 4x2 - 8
<=> 4x2 - 12x + 9 - 4x2 + 8 = 0
<=> 4x2 - 4x2 - 12x = -8 - 9
<=> -12x = -17
<=> \(x=\dfrac{17}{12}\)
Bài 4. Tìm x biết:
a. \(\dfrac{x}{5}=\dfrac{2}{5},\dfrac{3}{8}=\dfrac{6}{x},\dfrac{1}{9}=\dfrac{x}{27}\)
b. \(\dfrac{4}{x}=\dfrac{8}{6},\dfrac{3}{x-5}=\dfrac{-4}{x+2},\dfrac{x}{-2}=\dfrac{-8}{x}\)
a,2/5 = 2/5 ; 3/8=6/16 ; 1/9=3/27
b, 4/3=8/6 ; -1=-1 ; -4/-2=-8/4
tick cho mik nhé
a) x= 2, x= 8.(6 : 3) = 16, x= 1. (27 : 9)= 3
b) x= 6 : (8 : 4) = 3, x= -1, x= -2 . -8 = x.x => 16 = x2 => 42 = x2 => x=4
Tick cho mình đi