a) x-7=-5
b) 128-3.(x+4)=23
c) [(6x - 39) : 7].4=12
d (x:3-4).5=15
tìm x
a) x -7 = - 5
b) 128 - 3 . ( x + 4 ) = 23
c) [ ( 6x - 39 ) : 7 ] . 4 = 12
d) ( x : 3 - 4 ) . 5 = 15
cac ban oi giai giup minh nhe cam on
a) x - 7 = -5
=> x = -5 + 7
=> x = 2
b) 128 - 3 . (x + 4) = 23
=> 3.( x + 4) = 128 - 23
=> 3.( x + 4) = 105
=> x + 4 = 105 : 3
=> x + 4 = 35
=> x = 35 - 4
=> x = 31
c) [ ( 6x - 39 ) : 7 ].4 = 12
( 6x -39) : 7 = 12 :4
=> ( 6x - 39 ): 7 = 3
=> 6x - 39 = 3 x 7
=> 6x - 39 = 21
=> 6x = 21 + 39
=> 6x = 60
=> x = 60: 6
=> x = 10
d) ( x: 3 - 4) , 5 = 15
=> x: 3 - 4 = 15 : 5
=> x : 3 - 4 = 3
=> x: 3 = 3+4
=> x: 3 = 7
=> x = 7x 3
=> x =21
a) x -7=-5
x=-5 +7
x=2
b)128-3.(x+4)=23
3.(x+4)=128-23
3.(x+4)=105
x+4=105:3
x+4=35
x=35-4
x=31
c)[(6x-39):7].4=12
(6x-39):7=12:4
(6x-39):7=3
6x-39 =3.7
6x-39 =21
6x =21+39
6x =60
x =60:6
x =10
d)(x:3-4).5=15
x:3-4. =15:5
x:3-4 =3
x:3 =3+4
x:3 =7
x =7.3
x =21
Ai thấy đúng k mk nha
Bài 1 : tìm x
a. 128 - 3 . ( x+4 ) =23
b. [( 6x-39 ) : 7 ] . 4 = 12
c. ( x:3 - 4 ) . 5 = 15
d. | x+2 | =0
e. | x-5 | = |-7|
a, 128 - 3.( x + 4 ) = 23 b, [( 6x - 39 ) : 7 ] . 4 = 12 c, ( x : 3 - 4 ) . 5 = 15
3. ( x + 4 ) = 128 - 23 [(6x - 39 ) : 7 ] = 3 ( x : 3 - 4 ) = 3
3. ( x + 4 ) = 105 ( 6x - 39 ) = 21 x : 3 = 7
x + 4 = 35 6x = 21 + 39 x = 7 . 3
x = 35 - 4 6x = 60 x = 21
x = 31 x = 10 Vậy x = 21
Vậy x = 31 Vậy x = 10
Trl:
a. 128 - 3 . ( x + 4 ) = 23
=> 3 . ( x + 4 ) = 128 - 23
=> 3 . ( x + 4 ) = 105
=> x + 4 = 105 : 3
=> x + 4 = 35
=> x = 35 - 4
=> x = 31
Vậy x = 31
b. [( 6x - 39 ) : 7 ] . 4 = 12
=> [( 6x - 39 ) : 7 ] = 12 : 4
=> [( 6x - 39 ) : 7 ] = 3
=> ( 6x - 39 ) = 3 . 7
=> ( 6x - 39 ) = 21
=> 6x = 21 + 39
=> 6x = 60
=> x = 60 : 6
=> x = 10
Vậy x = 10
c. ( x : 3 - 4 ) . 5 = 15
=> ( x : 3 - 4 ) = 15 : 5
=> ( x :3 - 4 ) = 3
=> x : 3 = 3 + 4
=> x : 3 = 7
=> x = 7 . 3
=> x = 21
Vậy x = 21
d. | x + 2 | = 0
=> x + 2 = 0
=> x = 0 - 2
=> x = -2
Vậy x = -2
e. | x - 5 | = |-7|
=> | x - 5 | = 7
=> x - 5 = 7 hoặc x - 5 = -7
=> x = 7 + 5 hoặc x = -7 + 5
=> x = 12 hoặc x = -2
Vậy \(x\in\left\{12;-2\right\}\)
d, | x + 2 | = 0 e, | x - 5 | = | - 7 |
=> x + 2 = 0 | x - 5 | = 7
x = - 2 \(\orbr{\begin{cases}x-5=7\\x-5=-7\end{cases}}\)\(\Leftrightarrow\orbr{\begin{cases}x=12\\x=-2\end{cases}}\)
Vậy x = - 2 Vậy x = 12 hoặc x = - 2
Tìm x :
1) 128 - 3 . ( x + 4 ) = 23
2) [ ( 6x + 39 ) : 7 ] . 4 = 12
3) ( x : 3 - 4 ) . 5 = 15
4) | x + 2 | = 0
5) | x - 5 | = | - 7
6) | x - 3 | = 7 - ( -2 )
7) ( 3x - 24 ) . 73 = 2 . 7 4
8 ) | x - 3 | = | 5 | + | -7 |
9) ( 7 - x ) - ( 25 + 7 ) = -25
\(\left|x+2\right|=0\)
\(\Rightarrow x+2=0\)
\(\Rightarrow x=0-2\)
\(\Rightarrow x=-2\)
\(\left|x-5\right|=\left|-7\right|\)
\(\Rightarrow\left|x-5\right|=7\)
\(\Rightarrow\hept{\begin{cases}x-5=-7\\x-5=7\end{cases}}\Leftrightarrow\hept{\begin{cases}x=-7+5\\x=7+5\end{cases}}\Leftrightarrow\hept{\begin{cases}x=-2\\x=12\end{cases}}\)
\(\Rightarrow x\in\left\{-2;12\right\}\)
|x+2|=0
\(\Rightarrow\)x+2=0
\(\Rightarrow\)x= 0-2
\(\Rightarrow\)x= -2
x-7=-5
128-3.(x+4)=23
[(6.x-39):7].4=12
(x:3-4).5=15
a, x-7= -5
x = (-5)+7
x = 2
Vậy x = 2
b, 128-3.(x+4)=23
3.(x+4)=128-23
3.(x+4)= 105
x+4 = 105 : 3
x+4 = 35
x = 35-4
x = 31
Vậy x =31
c, [(6x-39) :7].4=12
[(6x-39):7] = 12:4
[(6x-39):7] = 3
6x-39 = 3.7
6x - 39 = 21
6x = 21+39
6x = 60
x = 60:6
x = 10
Vậy x = 10
d, (x:3-4).5=15
x:3-4 = 15 : 5
x:3-4 = 3
x: 3 = 7
x = 21
Vậy x= 21
a) x - 7 = -5 e) ( 3x - 24 ) . 73 = 2 . 74
b) 128 - 3 . ( x + 4 ) = 23 g) x - [ 42 + (-28)] = -8
c) [(6x - 39) : 7] . 4 = 12 i) 4 - ( 7 - x ) = x - ( 13 - 4 )
d) ( x : 3 - 4 ) . 5 = 15
trả lời đầy đủ nhất, nhanh nhất ticks luôn
a) x - 7 = - 5
x = - 5 + 7
x = 2
b) 128 - 3 . ( x + 4 ) = 23
3 . ( x + 4 ) = 128 - 23
3 . ( x + 4 ) = 105
x + 4 = 105 : 3
x + 4 = 35
x = 35 - 4
x = 31
c) [ ( 6x - 39 ) : 7 ] . 4 = 12
( 6x - 39 ) : 7 = 12 : 4
( 6x - 39 ) : 7 = 3
6x - 39 = 3 . 7
6x - 39 = 21
6x = 60
x = 10
d) ( x : 3 - 4 ) . 5 = 15
x : 3 - 4 = 3
x : 3 = 7
x = 21
a) x - 7= -5
x= -5 +7
x= 2
b) 128 -3 .(x+4)=23
3.(x+4)=128-23
3.(x+4)=105
x+4=105:3
x+4=35
x=35-4
x=31
c)[(6x-39):7].4=12
[(6x-39):7]=12:4
(6x-39):7=3
6x-39=7.3
6x-39=21
6x=21+39
6x=60
x=60:6
x=10
d) ( x :3 -4).5=15
x:3-4=15:5
x:3-4=3
x:3=4+3
x:3=7
x=7.3
x=21
e)(3x -2^4 ).7^3=2. 7^4
(3x-16).343=2.2401
(3x-16).343=4802
3x-16=4802:343
3x-16=14
3x=14+16
3x=30
x=30:3
x=10
g)x-[ 42+(-28)]=-8
x-14=-8
x=-8+14
x=6
i) 4-(7-x)=x -(13-4)
4-7+x=x-13+4
-3 + x= x-9
-3+x=-9+x
=> K có giá trị nào thỏa mãn -3+x=-9+x
=>x thuộc rỗng
a) 128 - 3 .( x + 4 ) = 23
b) [ ( 6x - 39 ) : 7 ] . 4 = 12
a) 128 - 3( x + 4 ) = 23
<=> 3x + 12 = 128 - 23 =105
<=> 3x = 105 - 12 = 93
<=> x = 31
b) [ ( 6x - 39 ) : 7 ] . 4 =12
<=> ( 6x - 39 ) : 7 = 12 / 4 =3
<=> 6x - 39 = 3 . 7 =21
<=> 6x = 21 + 39 = 60
<=> x =10
a,x-7 = -5 A. |x+2| = 0 1. (3x-2^4 ).7^3 =2.7^4
b 128-3.(x=4)=23 B.|x-5|=|-7| 2 . x-[42+(-28)]=-8
c , [ (6x-39):7 ] .4 =12 C.|X-3|=7 - (-2) 3 . |x-3| = |5|+|7|
d,(x:3-4).5=15 D . (7-x)-(25+7) =-25 4 . 15 - 2|x| = 13
E . |x|-5 = 3 5 . 4- (7-x)=x-(13-4)
A \(\left|x+2\right|=0\)
\(\Rightarrow x+2=0\)
\(\Rightarrow x=-2\)
vậy \(x=-2\)
B \(\left|x-5\right|=\left|-7\right|\)
\(\left|x-5\right|=7\)
\(\Rightarrow\orbr{\begin{cases}x-5=7\\x-5=-7\end{cases}}\Rightarrow\orbr{\begin{cases}x=12\\x=-2\end{cases}}\)
vậy ...
C \(\left|x-3\right|=7-\left(-2\right)\)
\(\left|x-3\right|=9\)
\(\Rightarrow\orbr{\begin{cases}x-3=9\\x-3=-9\end{cases}}\Rightarrow\orbr{\begin{cases}x=12\\x=-6\end{cases}}\)
vậy ....
E \(\left|x\right|-5=3\)
\(\left|x\right|=3+5\)
\(\left|x\right|=8\)
\(\Rightarrow\orbr{\begin{cases}x=8\\x=-8\end{cases}}\)
vậy ...
D \(\left(7-x\right)-\left(25+7\right)=-25\)
\(7-x-25-7=-25\)
\(-x=-25-7+25+7\)
\(-x=0\)
\(x=0\)
còn lại bạn tự làm nha
a) x - 7 = - 5
x = (- 5) + 7
x = 2
c) [ (6x - 39) : 7 ] .4 = 12
[ (6x - 39) : 7 ] = 12 : 4
[ (6x - 39) : 7 ] = 3
6x - 39) = 3.7
6x - 39 = 21 + 39
6x = 60
x = 60 : 6
x = 10
d) (x : 3 - 4). 5 = 15
x : 3 - 4 = 15 : 5
x : 3 - 4 = 3
x : 3 = 3 + 4
x : 3 = 7
x = 7.3
x = 21
P/s : mình chỉ làm được đến đó thôi mấy câu kia mình biết làm nhưng lười trình bày lắm , các bạn giúp mình nha .
bài 2 tim x
x-7=-5 a, | x+ 2|=0 (3x -24 ).73=2.74
128-3.(x+4)=23 |x-5|=|-7| x- [42+ (-28) ]=-8
[ (6x - 39) :7 ] .4=12 |x-3|=7-(-2) |x-3|=|5|+|-7|
(x:3-4).5=15 (7-x)-(25+7)=-25 4-(7-x)=x-(13-4)
x-7=-5
x=-5+7
x=2
vậy x=2
128-3.(x+4)=23
3.(x+4)=128-23
3.(x+4)=105
x+4=105:3
x+4=35
x=35-4
x=31
vậy x=31
|x+2|=0
x+2=0
x=0-2
x=-2
vậy x=-2
|x-5|=|-7|
x-5=7
x=7+5
x=12
vậy x=12
a) 92/9 + 13/5 - 56/9
b) 58/7 - (31/9 + 30/7)
c) 2/3 + 1/3 x 9/4 - 13/12
d) 41/8 - 7/4 : 11/5
e) 478/19 : 5/4 - 668/19 : 5/4
f) 32/21 x 49/45 : 16/22 x 15/33
g) 2020x2018+9 / 2019x2020-2011.
Giup minh voi minh dang can gap!!!
58/7 - (31/9 + 30/7)
= 58/7 - 31/9 - 30/7
= (58/7 - 30/7) - 31/9
= 28/7- 31/9
= 4 - 31/9 = 36/9 - 31/9
= 5/9
478/19÷(-5/4)-668/19÷(-5/4)
=(478/19-668/19):(-5/4)
=-10 . (-4/5)
=8