2,6 x X - 5= 613
[ X -15 ] -75=0
575- [6 x X +70 ] =445
315+ [125 -X ] = 435
X- 105 : 21 =15
[ X - 105 ] : 21=15
a/(x-15)-75=0
b/575-(6x+70)=445
c/315+(125-x)=435
d/x-105:21=15
e/(x-105):21=1
a) ( x - 15 ) - 75 = 0
x - 15 = 75
x = 75 + 15
x = 90
Vậy x = 90
b) 575 - ( 6x + 70 ) = 445
6x + 70 = 575 - 445
6x + 70 = 130
6x = 60
x = 10
Vậy x = 10
c) 315 + ( 125 - x ) = 435
125 - x = 120
x = 125 - 120
x = 5
Vậy x = 5
d) x - 105 : 21 = 15
x - 5 = 15
x = 20
Vậy x = 20
e) ( x - 105 ) : 21 = 1
x - 105 = 21
x = 21 + 105
x = 126
Vậy x = 126
a) (x-15)-75=0
x-15 = 0+75
x-15 = 75
x = 75 + 15
x = 90
b) 575-(6x+70)=445
6x+70 = 575-445
6x+70 = 130
6x = 130 - 70
6x = 60
x = 60:6
x = 10
d) x-105:21 = 15
x-105 = 15.21
x-105 = 315
x = 315 + 105
x = 420
e) (x-105):21 = 1
=> x-105 = 21
x = 105 + 21
x = 126
Tìm x:
a) ( x - 15 ) - 75 = 0 c) 315 + ( 125 - x ) = 435
x - 15 = 75 + 0 125 - x = 435 - 315
x - 15 = 75 125 - x = 120
x = 75 + 15 x = 125 - 120
x = 90 x = 5
b) 575 - ( 6x + 70 ) = 445 d) x - 105 : 21 = 15
6x + 70 = 575 - 445 x - 105 = 15 x 21
6x + 70 = 130 x - 105 = 315
6x = 130 - 70 x = 315 + 105
6x = 60 x = 420
x = 60 : 6
x = 10
(x – 15 ) – 75 = 0 b) 575- (6x +70) =445
c) x –105 : 21 =15 d) (x - 105) :21 = 15
a) \(\left(x-15\right)-75=0\\ \Leftrightarrow x-15=75\\ \Leftrightarrow x=90\)
b) \(575-\left(6x+70\right)=445\\ \Leftrightarrow6x+70=130\\ \Leftrightarrow6x=60\\ \Leftrightarrow x=10\)
c) \(x-105:21=15\\ \Leftrightarrow x-5=15\\ \Leftrightarrow x=20\)
d) \(\left(x-105\right):21=15\\ \Leftrightarrow x-105=315\\ \Leftrightarrow x=420\)
a) ( x - 15 ) - 75 = 0
x -15 = 75 + 0
x - 15 = 75
x= 75 + 15
x = 90
b) 575- (6x +70) =445
6x + 70 = 575 - 545
6x + 70 = 130
6x = 130 - 70
6x = 60
x = 60 : 6
x = 10
c) x –105 : 21 =15
x –105 = 15 x 21
x -105 = 315
x = 315 + 105
x = 420
d) (x - 105) :21 = 15
x - 105 = 21
x = 105 + 21
x = 126
a) (x - 5) - 75 = 0
x - 5 = 75 + 0
x - 5 = 75
x = 75 + 5
x = 80
b) 575 - (6x + 70) = 445
6x + 70 = 575 - 445
6x + 70 = 130
6x = 130 - 70
6x = 60
x = 60 : 6
x = 10
c) x - 105 : 21 = 15
x - 5 = 15
x = 15 + 5
x = 20
d) (x - 105) : 21 = 15
x - 105 = 15 x 21
x -150 = 135
x = 135 + 150
x = 285
bài 2 tìm x
1 ( x - 17 ) * 17 = 0
2 32 ( x - 11 ) = 32
3 ( x - 25 ) - 75 = 0
4 575 -( 6 * x + 70 ) = 445
5 315 + ( 125 - x ) = 435
6 x- 105 : 21 = 15
7 ( x - 105 ) : 21 = 15
8 ( x - 38 ) : 19 = 12
9 ( x - 15 ) * ( x - 19 ) = 0
10 96 - 3 ( x + 1 ) = 42
1) (x-17)*17=0
x-17=0
x=17
2) 32(x-11)=32
x-11=1
x=12
3) (x-25)-75=0
x-25=75
x=3
4) 575-(6*x+70)=445
6*x+70=130
6*x=60
x=10
5) 315+(125-x)=435
125-x=120
x=5
6) x-105:21=15
x-5=15
x=20
7) (x-105):21=15
x-105=315
x=420
8) (x-38):19=12
x-38=228
x=266
9) (x-15)*(x-19)=0
=>x-15=0 hoặc x-19=0
x=15 hoặc x=19
10) 96-3(x+1)=42
3(x+1)=54
x+1=18
x=17
a) ( x - 17 ) . 17 = 0
=> x - 17 = 0 : 17
=> x - 17 = 0
=> x = 0 + 17
=> x = 17
b) 32 . ( x - 11 ) = 32
=> x - 11 = 32 : 32
=> x - 11 = 1
=> x = 1 + 11
=> x = 12
c) ( x - 25 ) - 75 = 0
=> x - 25 = 0 + 75
=> x - 25 = 75
=> x = 75 + 25
=> x = 100
d) 575 - ( 6 . x + 70 ) = 445
=> 6 . x + 70 = 575 - 445
=> 6 . x + 70 = 130
=> 6 . x = 130 - 70
=> 6 . x = 60
=> x = 60 : 6
=> x = 10
e) 315 + ( 125 - x ) = 435
=> 125 - x = 435 - 315
=> 125 - x = 120
=> x = 125 - 120
=> x = 5
f) x - 105 : 21 = 15
=> x - 5 = 15
=> x = 15 + 5
=> x = 20
g) ( x - 105 ) : 21 = 15
=> x -105 = 15 . 21
=> x - 105 = 315
=> x = 315 + 105
=> x = 420
h) ( x - 38 ) : 19 = 12
=> x - 38 = 12 . 19
=> x - 38 = 228
=> x = 228 + 38
=> x = 266
i) ( x - 15 ) . ( x - 19 ) = 0
=> x - 15 = 0 => x = 0 + 15 => x = 15
x - 19 = 0 => x = 0 + 19 = x = 19
=> x = 15 ; 19
j) 96 - 3( x + 1 ) = 42
=> 3( x + 1 ) = 96 - 42
=> 3( x + 1 ) = 54
=> x + 1 = 54 : 3
=> x + 1 = 18
=> x = 18 - 1
=> x = 17
Bài 7. Tìm x ϵ N biết:
a) (x – 15 ) – 75 = 0
b) 575- (6x +70) =445
c) x –105 : 21 =15
d) (x - 105) :21 = 15
giải đầy đủ giúp mik với
Bài 7:
a)(x-15)-75=0
⇔x-15=75
⇔x=90
b)575-(6x+70)=445
⇔6x+70=130
⇔6x=60
⇔x=10
c)x-105:21=15
⇔x-5=15
⇔x=20
d)(x-105):21=15
⇔x-105=315
⇔x=420
tìm x
a; 35-15+x=70
b; 568-(2.x+14)=15
c; x-105:21=15
d; (x-105).21=15
a) 35-15+x=70
=> 20+x=70
=> x=50
b) 568-(2x+14)=15
=> 2x+14=553
=> 2x=539
=> x=269,5
c) x-105:21=15
=> x-5=15
=> x=20
d) (x-105)*21=15
=> x-105=5/7
=> x=5/7+105
=> x=740/7
a, 35 - 15 + x = 70 b, 568 - (2.x + 14 )= 15
x = 70 - 35 + 15 2.x + 14 = 568 - 15
x = 50 2.x + 14 =553 => 2.x =553-14=539 =>x=539 : 2 =269.5
c, x - 105 : 21 =15 d, (x - 105) . 21 = 15
x - 105 = 15 x 21 x - 105 = 15 : 21
x - 105 = 315 x - 105 = \(\frac{5}{7}\)
x = 315+105 x = \(\frac{5}{7}\)+ 105
x = 420 x = \(\frac{740}{7}\)
a/ 35-15+x=70 b/ 569-(2x+14)=15 c/ x-105:21=15 d/(x-105).21 =15
20+x =70 2x+14 =569-15 x-5 =15 x-105 =15:21
x =70-20 2x+14 =554 x =15+5 x-105 =5/7
x =50 2x =554-14 x =20 x=5/7+105
x=740/7
2x =540
x =540 : 2
x =270
Tìm x
a) ( x - 15 ) - 15 = 0
b) 575 - ( 6x + 70 ) = 445
c) 315 + ( 125 - x ) = 435
d) x - 105 : 21 = 15
a ) ( x - 15 ) - 15 = 0
x - 15 = 15
x = 15 + 15
x = 30
a ) ( x - 15 ) - 15 = 0
x - 15 = 0 + 15
x - 15 = 15
tìm x thuộc N, biết :
a) x - 105 : 21 = 15
b) ( x - 105 ) : 21 = 15
c) 315 + ( 125 - x ) = 435
a) x - 105 : 21 = 15
x - 5 = 15
=> x = 20
b) ( x - 105 ) : 21 = 15
x - 105 = 315
=> x = 420
c) 315 + ( 125 - x ) = 435
125 - x = 120
=> x = 5
a)x - 105 : 21 = 15
x - 5 =15
x =20
b) (x - 105) :21=15
x -105 =315
x =420
c) 315+ (125 - x ) =435
125 - x =-120
x =5
tìm x biết:
a,315+(125-x)=435
b,x:41=32
c,(x-105):21=15
d,x-105:21=15
,
a) \(315+\left(125-x\right)=435\)
\(\Leftrightarrow125-x=435-315\)
\(\Leftrightarrow125-x=120\)
\(\Leftrightarrow x=125-120\)
\(\Leftrightarrow x=5\)
b) \(x:41=32\)
\(\Leftrightarrow x=32\cdot41\)
\(\Leftrightarrow x=1312\)
c) \(\left(x-105\right):21=15\)
\(\Leftrightarrow x-105=15\cdot21\)
\(\Leftrightarrow x-105=315\)
\(\Leftrightarrow x=315+105\)
\(\Leftrightarrow x=420\)
d) \(x-105:21=15\)
\(\Leftrightarrow x-5=15\)
\(\Leftrightarrow x=15+5\)
\(\Leftrightarrow x=20\)
a, 315 + ( 125 - x ) = 435
( 125 - x) = 435 - 315
( 125 - x ) = 320
x = 320 - 125
x = 195
bạn văn quang long tính sai rồi 435-315=120 chứ
Tìm x thuộc N biết :
a) (x-15)x15=0
b) 32(x-10)=32
c)315 (125-x)=435
d) (x-15)-75=0
e) 575-(6x 70)=445
g)x-105:21=15'
câu d mk làm sai rồi
d) (x-15)-75=0
x-15=0+75=75
x=75+15=90
a) (x-15)x15=0
=>x-15=0
x=0+15=15
b) 32(x-10)=32
x-10=32:32=1
x=1+10=11
c)315 (125-x)=435
125-x=435-315=120
x=125-120=5
d) (x-15)-75=0
=>x-15=0
x=0+15=0
e) 575-(6x 70)=445
6x70=575-445=130
6x=130:70=13/7
x=13/7:6=13/42
g)x-105:21=15'
x-5=15
x=15+5=20
**** nhé