Tìm x :
a ) 7 ( x-4 ) = 74 : 73
b ) 2x-105 : 21=15
c ) 15-5 ( x- 1 ) = 10
d ) ( x-12 ) :3 = 6
e ) 24 + 5 . x = 75 : 73
g ) x + 12.3=40
h ) 2x-138=23.32
i ) 231- ( x-6 ) = 1339 : 13
k ) 3x + 2x = 25
l ) 2x-42 : 8 = 12
m ) 12 ( x-1 ) :3=43- 23
n ) 128 : ( x-1 )2 =2
o ) x-34=2.32-1
ô ) 3+2x-1 = 24 - [ 42 -(22-1 ) ]
giúp mình tìm x với mai mình học rồi
a) 7 ( x - 4) = 74-3
7 ( x-4) = 7
x - 4 = 1
<=> x = 1 + 4 = 5
b) 2x - 105 : 21 = 15
2x - 5 = 15
2x = 15+ 5
2x = 20
=> x = 10
c) 15 - 5 (x-1) = 10
15 - 5x -1 = 10
<=> 5x-1 = 15-10
<-> 5x - 1 = 5
5x = 5+1
5x = 6
=> x = 6/5
d) (x-12):3 = 6
x-12 = 6.3
x - 12 = 18
x = 18 + 12
x= 30
e) 24 + 5x = 72
5x = 72-24
5x = 25
=> x = 25 : 5 = 5
G) x+12.3 = 40
x+ 36 = 40
=> x = 40-36= 4
h) 2x - 138 = 25
2x = 25 + 138
2x = 170
=> x = 170:2 = 85
i ) 231 - (x-6) = 103
x-6 = 231 - 103
x-6 = 128
x= 128 + 6 = 134
k ) 3x+2x=25
5x=25
=> x = 25 : 5 = 5
l ) 2x - 16:8 = 12
2x - 2 = 12
<=> 2x = 14
=> x= 7
m ) 12 ( x-1) :3 = 56
12 (x-1) = 56 . 3
12 (x-1) = 168
x- 1 = 168 : 12
x - 1 = 14
=> x= 15
n ) 128 : (x-1)2=2
(x-1)2= 128 : 2
(x-1)2 = 64
=> x = 9
o) x- 34 = 17
=> x = 17 +34 = 51
Phù mệt quá !!
đúng cho mình nhen bạn.
Làm mệt quá chời quá đất luôn.
a) 7 ( x-4) = 7^4 : 7^3
7(x-4)=7
X-4=1
x=5.
Vậy,..
\(7\times\left(x-4\right)=7^4:7^3\)
\(7\times\left(x-4\right)=7\)
\(x-4=7:7\)
\(x-4=1\)
\(\Rightarrow x=5\)
