Tìm x :
( x-2 ) . 3 = 18
135 - 3 (x+1)=30
(123-x)-72=28
(158-x):7=20
42.x=39.42-37.42
(2400+4600)-3.x=1200
[(6.x-72):2-84 ] .28=5628
42x=39.42-37.42
tìm x thuộc N biết
a 219-7(x+1)=100
b 123-5.(x+40)=38
c (3x-6).3=34
d 42.x=39.42-37.42
a,219-7(x+1)=100
7(x+1)=219-100
7(x+1)=119
x+1= 119:7
x+1= 17
x= 17-1
x=16
Vậy x=16
b,123-5.(x+40)=38
5.(x+40)=123-38
5.(x+40)=85
x+40= 85:5
x+40=17
x= 17-40
x=-23
Vậy x=-23
c,(3x-6).3=34
3x-6 =34:3
3x-6 =33
3x-6 =27
3x =27+6
3x =33
x =33:3
x =11
Vậy x=11
d, 42.x=39.42-37.42
42.x=1638-1554
42.x=84
x =84:42
x =2
Vậy x=2
Nhớ nhé, học giỏi ^^
Tìm số tự nhiên x,biết:
a)(2600+6400)-3.x=1200
b)[(6.x-72):2-84].28=5628
c)2.x-138=23.32
d)42.x=39.42-37.42
a) ( 2600 + 6400 ) - 3 . x = 1200
9000 - 3 . x = 1200
3 . x = 9000 - 1200
3 . x = 7800
x = 7800 : 3
x = 2600
b) [ ( 6 . x - 72 ) : 2 - 84 ] . 28 = 5628
[ ( 6 . x - 72 ) : 2 - 84 ] = 5628 : 28
[ ( 6 . x - 72 ) : 2 - 84 ] = 201
( 6 . x - 72 ) : 2 = 201 + 84
( 6 . x - 72 ) : 2 = 285
( 6 . x - 72 ) = 285 . 2
( 6 . x - 72 ) = 570
6 . x = 570 + 72
6 . x = 642
x = 642 : 6
x = 107
c) 2 . x - 138 = 23 . 32
2 . x - 138 = 8 . 9
2 . x - 138 = 72
2 . x = 72 + 138
2 . x = 210
x = 210 : 2
x = 105
d, 42 . x = 39 . 42 - 37 . 42
42 . x = 42 . ( 39 - 37 )
42 . x = 42 . 2
\(\Rightarrow\) x = 2
Tìm số tự nhiên x, biết:
a) (2600 + 6400) - 3.x = 1200; b) [(6.x - 72) : 2 -84] .28 = 5628;
c) 2x - 138 = 23.32; d) 42x = 39.42 - 37.42.
kb nhé !!!
a) (2600 + 6400) - 3.x = 1200 c)2x-138=2^3 . 3^2
9000 - 3.x=1200 2x-138=8.9
3.x=9000-1200 2x-138=72
3.x=7800 2x=72+138
x=7800:3 2x=210
x=2600 x=210:2
b) [(6x-72):2-84].28=5628 x=105
[(6x-72):2-84]=5628:28 d)42x = 39.42-37.42
(6x-72):2-84=201 42x = (39-37).42
(6x-72):2=201+84 42x = 2.42
(6x-72):2=285 42x=84
6x-72=285.2 x=84:42
6x-72=570 x=2
6x=570+72
6x=642
x=642:6
x=107
a, ( 2600 + 6400 ) - 3x = 1200
=> 9000 - 3x - 1200
=> 3x = 9000 - 1200 = 7800
=> x = 7800 : 3 = 2600
b, [( 6x - 72) : 2 - 84] .28 = 5628
=> (6x - 72 ) : 2 - 84 = 5628 : 28 = 201
=> ( 6x - 72) : 2 = 201 + 84 = 285
=> 6x - 72 = 285 x 2 = 570
=> 6x = 570 + 72 = 642
=> x = 642 : 6 = 107
a) 10-5 (x-3)=45 b)318 - (x-7)=138:3 c)42.x = 39.42- 37.42
d) (158-x):7 =120
Ai nhanh va d thi tick cho
\(10-5\left(x-3\right)=45\)
\(5\left(x-3\right)=10-45\)
\(5\left(x-3\right)=-35\)
\(\left(x-3\right)=-35:5\)
\(\left(x-3\right)=-7\)
\(x=-7+3\)
\(x=-4\)
a, 10 - 5(x - 3) = 45
=> 5x - 15 = 10 - 45
=> 5x - 15 = -35
=> 5x = -35 + 15
=> 5x = -20
=> x = -20 : 5
=> x = -4
Vậy x = - 4
b , 318 - (x - 7) = 138 : 3
=> 318 - (x - 7) = 46
=> x - 7 = 318 - 46
=> x - 7 = 272
=> x = 272 + 7
=> x = 279
Vậy x = 279
c, 42x = 39.42 - 37.42
=> 42x = 42.(39 - 37)
=> 42x = 42 . 2
=> 42x = 84
=> x = 84 : 42
=> x = 2
Vậy x = 2
d, (158 - x) : 7 = 120
=> 158 - x = 120.7
=> 158 - x = 840
=> x = 158 - 840
=> x =-682
Vậy x = -682
a) 10-5 (x-3)=45
=> 5(x - 3) = -35
=> x - 3 = -7
=> x = -4
vậy_
b)318 - (x-7)=138:3
=> 318 - (x - 7) = 46
=> x - 7 = 272
=> x = 279
vậy_
c)42.x = 39.42- 37.42
=> 42x = 42(39 - 37)
=> x = 42.2 : 42
=> x = 2
vậy_
d) (158-x):7 =120
=> 158 - x = 840
=> x = -682
vậy_
1. 13-(x-5)=8 8. (x-5)^6=(x-5)^8
2. 8-(x-10)=23-(-4+12) 9. (3-x).(x-3)=0
3. 134-5(x+4)=34 10. -32-(x-5)=0
4. |5-x|=7
5. 20+8.(x+3)=5^2.4
6. 42x=39.42-37.42
7. |x|=2-(-7)
bài 1 tìm số nguyên x bt
a)(3x-2^4).7^14=2.7^15
b)42x=39.42-37.42
b) 42x=39.42-37.42
42x=42(39-37)
42x=42.2
Vì 42x=42.2
nên x=2
Vậy x=2
a) (3x-24).714=2.715
3x-24=2.715:714
3x-24=2.7
3x-16=14
3x=14+16
3x=30
x=30:3
x=10
a) 3x - 18 . 28 : 14 = 308
b) 38 + /x/ = ( -12 ) +65
c) 15 +3 ( x-1) : 5 = 30
d) 5. ( 7-3x ) + 7. ( 2+2x ) = 1
e ) 3. / x - 7 ) =21
g) [( 6x - 72 ) : 2 - 84 ] : 28 =5628
h) 123 - 5( x+4 ) = 28
p) 14 ( x - 3 ) - 138 = 73
t) /x/ - 5 = 2
v) 4x - 72 = /100 - 8 . 25 /
a) \(3x-18.28:14=308\)
\(=>3x-36=308\)
\(=>3x=344\)\(\)
\(=>x=\frac{344}{3}\)
\(\)b)\(38+\left|x\right|=\left(-12\right)+65\)
\(=>38+\left|x\right|=53=>\left|x\right|=15=>\orbr{\begin{cases}x=15\\x=-15\end{cases}}\)
c)\(15+3.\left(x-1\right):5=30\)
\(=>15+3.\left(x-1\right)=150\)
\(=>3.\left(x-1\right)=135\)
\(x-1=45=>x=46\)
d) \(5.\left(7-3x\right)+7.\left(2+2x\right)=1\)
\(=>35-15x+14+14x=1\)
\(=>49-x=1=>x=48\)
e)\(3.\left(x-7\right)=21\)
\(=>x-7=7=>x=14\)
g)\(\left[\left(6x-72\right):2-84\right]:28=5628\)
\(\left(6x-72\right):2-84=157584\)
\(\left(6x-72\right):2=157668\)
\(6x-72=315336\)
\(6x=315408=>x=52568\)
h)\(123-5\left(x+4\right)=28\)
\(5.\left(x+4\right)=95\)
\(x+4=19=>x=15\)
p)\(14.\left(x-3\right)-138=73\)
\(14.\left(x-3\right)=211\)
\(x-3=\frac{211}{14}=>x=\frac{253}{14}\)
\(t\)
\(\left|x\right|-5=2\)
\(\left|x\right|=7=>\orbr{\begin{cases}x=7\\x=-7\end{cases}}\)
v)\(4x-72=\left|100-8.25\right|\)
\(4x-72=\left|-100\right|\)
\(4x-72=100=>4x=172=>x=43\)
cậu có thể tham khảo bài làm trên đây ạ, chúc cậu học tốt ^^
tìm x
42x= 39.42-37.42
42x= 42.(39-37)
42x=42. 2
42x=84
=> x=2
\(42x=39.42-37.42\)
\(\Leftrightarrow42x=84\)
\(\Leftrightarrow x=2\)
\(42x=39.42-37.42\)
\(42x=42\left(19-37\right)\)
\(42x=42.2\)
\(\Leftrightarrow x=2\)