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
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
( x-2) .3 =18 135-3(x+1)=30
(x-2) =18:3 3(x+1)=135-30
(x-2) =6 3(x+1)=105
x =6+2 x+1 =105:3
x =8 x+1 =35
x =35-1
x =34
(123-x)-72=28 (158-x):7=28
(123-x) =28+72 (158-x) =28.7
(123-x) =100 (158-x) =784
x =123-100 x =158-784
x =23 x =-626
42.x=39.42-37.42
42.x=42.(39-37)
42.x=42.2
x=42.2:42
x =2
bài này dài lắm đó k mik nha
( x - 2 ) . 3 = 18 135 - 3( x + 1 ) = 30 ( 123 - x ) - 72 = 28
x - 2 = 18 : 3 3( x + 1 ) = 135 - 30 123 - x = 28 + 72
x - 2 = 6 3( x + 1 ) = 105 123 - x = 100
x = 6 + 2 x + 1 = 105 : 3 x = 123 - 100
x = 8 x + 1 = 35 x = 23
x = 35 - 1
x = 34
( 158 - x ) : 7 = 20 42 . x = 39 . 42 - 37 . 42
158 - x = 20 x 7 42 . x = 42 . ( 39 - 37 )
158 - x = 140 42 . x = 84
x = 158 - 140 x = 84 : 42
x = 18 x = 2
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
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
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)
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_
bài 1. a. 3^6 :3^2+2^3.2^2
B. (39.42-37.42):42 = ??
???
a, 3^6: 3^2+ 2^3 . 2^2
= 3^4 + 2^5
= 81 + 32
= 113
b, (39.42 - 37.42) : 42
= (39- 37) . 42 : 42
= 2 . 42 : 42
= 84 : 42
= 2
Cái này có thể chưa hợp lý lắm
(2400+4600)-3.x=1200
[(6.x-72):2-84 ] .28=5628
42x=39.42-37.42
tìm x
42x= 39.42-37.42
42x= 42.(39-37)
42x=42. 2
42x=84
=> x=2
\(42x=39.42-37.42\)
\(\Leftrightarrow42x=84\)
\(\Leftrightarrow x=2\)
\(42x=39.42-37.42\)
\(42x=42\left(19-37\right)\)
\(42x=42.2\)
\(\Leftrightarrow x=2\)
tìm x biết :42x=39.42-37.42