[x cộng 32 ] - 17 .2 = 42
575- [6x cộng 70 ] =25
315 cộng [ 125 -x] = 435
[x -105] chia 21 = 15
[ 61 cộng [ 51 -x ] . 17 = 1785
575-[6x+60]=25
[6x+60]=575-25
[6x+60]=550
suy ra:
6x+60=550 hoặc 6x+60=-550
6x =550-60 6x =-550-60
6x =490 6x =-610
vậy...
[x+32]-17.2=42
[x+32]-17 =42:2
[x+32]-17 =21
[x+32] =21+17
[x+32] =28
suy ra:
x+32=28 hoặc x+32=-28
x =28-32 x =-28-32
x =-4 x =-60
315+[125-x]=435
[125-x]=435-315
[125-x]=120
suy ra:
125-x=120 hoặc 125-x=-120
x=125-120 x=125-(-120)
x=5 x=245
vậy...
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
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 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
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
(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
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
Làm nhanh nha mn:
a)(x-13)-17=0
b)315+(125-x)=435
c)575-(6x+70)=445
d)(x-105):21=15
e)102-3.(x+1)=27
a)(x-13)-17=0
=>X-13. = 0+17
=>x-13. =17
=>x. = 17+13
=>x. = 30
b)315+(125-x)=435
=>(125-x). =435-315
=>(125-x). =120
=>.x. = 5
c)575-(6x+70)=445
=>(6x+70). =575-445
=> (6x+70). =130
=>. 6x. =130-70
=>6x. =60
=>x. =60:6
=>X. =10
a) (x-13)-17=0 (x-13) =0+17 x-13 =17 x = 17+13 x =30
d)(x-105):21=15
=>(X-105). =15.21
=>(x-105). =315
=>x. = 315+105
=>x. =420
e)102-3.(x+1)=27
=> 3.(x+1.) =102-27
=>3.(x+1) =75
=>x+1. =75:3
=>x+1. =25
=> x. = 25-1
x. =24
