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a) (x: 8 - l).2 = 1.14 nên x : 8 - 1 = 7. Do đó x = 64.
b) (2x + 3).30 = 25.6 nên 2x + 3 = 5. Do đó x = 1.
c) 6.(2x - 7) = 9.(x - 3) nên 12x - 42 = 9x - 27.
Do đó 3x = 15. Vậy x = 5.
d) -7.(x + 27) = 6.(x + l) nên -7x - 189 = 6x + 6.
Do đó 13x = -195. Vậy x = -15.
1
a, 4x - 3x + 1 = 5
x =5-1
x =4
Vậy x=4
b, (2x - 4 ) . 3x =0
=> 2x - 4 =0 hoặc 3x = 0
=> 2x =4 hoặc x=0
=> x =2 hoặc x=0
vậy x= 2 hoặc x=0
c, x . ( x -1 ) - ( x-1 )=0
(x-1) . (x-1 ) =0
(x-1)2 =02
x-1 =0
x =1
vậy x=1
2/ a, 7 . (x - 1 ) = 6x + 3
7x -7 = 6x +3
7x - 6x =7+3
x =10
vậy x=10
b, 8 . ( 2x - 3 ) -15x =4
16x - 24 -15x =4
16x - 15x =4+24
x =28
vậy x=28
c, 7 . 10 + ( x-1 ) .2 =100
70 + 2x -2 =100
2x -2 =100-70
2x -2 =30
2x =30+2
2x =32
x =16
vậy x=16
chúc bn học tốt
Giải:
a) \(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-1}{3}\)
\(\dfrac{-5}{6}-x=\dfrac{1}{4}\)
\(x=\dfrac{-5}{6}-\dfrac{1}{4}\)
\(x=\dfrac{-13}{12}\)
b) \(2.\left(x-\dfrac{1}{3}\right)=\left(\dfrac{1}{3}\right)^2+\dfrac{5}{9}\)
\(2.\left(x-\dfrac{1}{3}\right)=\dfrac{1}{9}+\dfrac{5}{9}\)
\(2.\left(x-\dfrac{1}{3}\right)=\dfrac{2}{3}\)
\(x-\dfrac{1}{3}=\dfrac{2}{3}:2\)
\(x-\dfrac{1}{3}=\dfrac{1}{3}\)
\(x=\dfrac{1}{3}+\dfrac{1}{3}\)
\(x=\dfrac{2}{3}\)
c) \(\left|2x-\dfrac{3}{4}\right|-\dfrac{3}{8}=\dfrac{1}{8}\)
\(\left|2x-\dfrac{3}{4}\right|=\dfrac{1}{8}+\dfrac{3}{8}\)
\(\left|2x-\dfrac{3}{4}\right|=\dfrac{1}{2}\)
\(\Rightarrow\left[{}\begin{matrix}2x-\dfrac{3}{4}=\dfrac{1}{2}\\2x-\dfrac{3}{4}=\dfrac{-1}{2}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{5}{8}\\x=\dfrac{1}{8}\end{matrix}\right.\)
d) \(\dfrac{2}{3}x+\dfrac{1}{6}x=3\dfrac{5}{8}\)
\(x.\left(\dfrac{2}{3}+\dfrac{1}{6}\right)=\dfrac{29}{8}\)
\(x.\dfrac{5}{6}=\dfrac{29}{8}\)
\(x=\dfrac{29}{8}:\dfrac{5}{6}\)
\(x=\dfrac{87}{20}\)
a) ( 2x - 3 ) - ( x - 5 ) = ( x + 7 ) - ( x + 2 )
<=> 2x - 3 - x + 5 = x + 7 - x - 2
<=> x = 3
b)(7x-5)-(6x+4)=(2x+3)-(2x+1)
<=> 7x - 5 - 6x - 4 = 2x + 3 - 2x - 1
<=> x = 11
c)(9x-3)-(8x+5)=(3x+2)
<=> 9x - 3 - 8x - 5 = 3x + 2
<=> -2x = 10
<=> x = -5
d)(x+7)-(2x+3)=(3x+5)-(2x+4)
<=> x + 7 - 2x - 3 = 3x + 5 - 2x - 4
<=> -2x = -3
<=> x = 3/2
ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠ
A=-(3x+7)+(5x-2)+(2x-10)
=-3x-7+5x-2+2x-10
=(-3x+5x+2x)-(7+2+10)
=4x-19
B = (6x+8)-(4x-5)-3x
= 6x+8-4x+5-3x
= (6x-4x-3x) + (8+5)
= -x + 13
= 13-x
C = 2(5x+3) - (2x-1) + 12
= 10x+6 - 2x + 1 + 12
= (10x-2x) + (6+1+12)
= 8x + 19
D = (x+7)-3(x+1)+2x-5
= x+7-3x-3+2x-5
= (x-3x+2x) + (7-3-5)
= -1
a) |2x + 8| = 3x
=> 2x + 8 = 3x hoặc - (2x + 8) = 3x
=> 3x - 2x = 8 hoặc - 2x - 3x = 8
=> x = 8 hoặc -5x = 8
=> x = 8 hoặc x = -5/8
b) |7 - 6x| = 1 - 2x
=> 7 - 6x = 1 - 2x hoặc -(7 - 6x) = 1 - 2x
=> 6x + 2x = 7 + 1 hoặc -7 + 6x = 1 + (- 2x)
=> 8x = 8 hoặc -7 - 1 = 6x - (- 2x)
=> x = 1 hoặc -8 = 8x
=> x = 1 hoặc x = -1