Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Z biết: 1) x + 35 = 8 ; 2) 15 – ( 4 – x) = 6 ; 
Z thì: M = a(a + 3) – a(a – 5) – 8 là bội của 8. 
; 
; 
2) 
; 2) 
3) 
4) 
6) 
7) 
![[Năm 2021] Đề thi Học kì 1 Toán lớp 6 có đáp án (3 đề) | Kết nối tri thức](file:///C:/Users/Anu/AppData/Local/Temp/msohtmlclip1/01/clip_image029.png)
?
1: =>x=8-35=-27
2: =>15-4+x=6
=>x+11=6
hay x=-5
3: =>-30+25-x=-1
=>x+5=1
hay x=-4
4: =>x-(-13)=-8
=>x+13=-8
hay x=-21
5: =>x-29-17+38=-9
=>x-8=-9
hay x=-1
15-(4-x)=6
⇒15-4+x=6
⇒11+x=6
⇒x=-5
x-(12-25)=-8
⇒x+13=-8
⇒x=-21
(x-29)-(17-38)=-9
⇒x-29+21=-9
⇒x-8=-9
⇒x=-1
-30+(25-x)=-1
⇒-30+25-x=-1
⇒-5-x=-1
⇒x=-4
a, 15 - ( 4 - x ) = 6
⇒ 15 - 4 + x = 6
⇒ 11+ x = 6
⇒ x = -5
c, x - ( 12 - 25 ) = -8
⇒ x + 13 = -8
⇒ x = -21
d, ( x - 29 ) - ( 17 - 38 ) = -9
⇒ x - 29 + 21 = -9
⇒ x - 8 = -9
⇒ x = -1
b, - 30 + ( 25 - x ) = -1
⇒ - 30 + 25 - x = -1
⇒ -5 - x = -1
⇒ x = -4
a, \(15-4+x=6\) ⇒ \(11-x=6\) ⇒ \(x=5\)
b, \(-30+25-x=-1\) ⇒ \(-5-x=-1\) ⇒ \(x=-4\)
c, \(x-12+25=-8\Rightarrow x+13=-8\) ⇒ \(x=-21\)
d, \(x-29-17+38=-9\Rightarrow x-8=-9\Rightarrow x=-1\)
1. Tìm x biết:
a) 15 – ( 4 – x) = 6
4-x=15-6
4-x=9
x=4-9
x=-5
b) - 30 + ( 25 – x) = - 1
25-x=-1-(-30)
25-x=29
x=25-29
x=-4
c) x – ( 12 – 25) = -8
x+13=-8
x=-8-13
x=-21
d) ( x – 29 ) – ( 17 – 38 ) = - 9
(x-29)-(-21)=-9
(x-29)=-9-21
x-29=-30
x=-30+29
x=-1
2. Tìm số nguyên x biết:
a) x – 5 = - 1
x=-1+5
x=4
b) x + 30 = - 4
x=-4-30
x=-34
c) x – ( - 24) = 3
x+24=3
x=3-24
x=-21
d) 22 – ( - x ) = 12
22+x=12
x=12-22
x=-10
e) ( x + 5 ) + ( x – 9 ) = x + 2
x+5+x-9=x+2
x+x-x=2-5+9
x=6
f) ( 27 – x ) + ( 15 + x ) = x – 24
27-x+15+x=x-24
-x+x+x=-24-27-15
x=-66
3. Tìm x biết:
a) 461 + (x - 45) = 387
x-45=387-461
x-45=-74
x=-74+45
x=-29
b) 11 - (-53+ x ) = 97
-53+x=11-97
-53+x=-86
x=-86-(-53)
x=-33
c) - ( x + 84) + 213 = -16
-(x+84)=-16-213
-(x+84)=-229
x+84=229
x=229-84
x=145
a) Ta có: \(15-\left(4-x\right)=6\)
\(\Leftrightarrow15-4+x=6\)
\(\Leftrightarrow11+x=6\)
\(\Leftrightarrow x=-5\)
Vậy: x=-5
b) Ta có: \(-30+\left(25-x\right)=-1\)
\(\Leftrightarrow-30+25-x=-1\)
\(\Leftrightarrow-5-x=-1\)
\(\Leftrightarrow x=-5+1=-4\)
Vậy: x=-4
c) Ta có: \(x-\left(12-25\right)=-8\)
\(\Leftrightarrow x-12+25+8=0\)
\(\Leftrightarrow x+21=0\)
\(\Leftrightarrow x=-21\)
Vậy: x=-21
d) Ta có: \(\left(x-29\right)-\left(17-38\right)=-9\)
\(\Leftrightarrow x-29-17+38+9=0\)
\(\Leftrightarrow x+1=0\)
\(\Leftrightarrow x=-1\)
Vậy: x=-1
a.x-4=15-6 b.25-x=-30-(-1) c.x-(-13)=-8
x-4=9 25-x=-29 x+13=-8
x=9+4 x=25-(-29) x=-8-13
x=13 x=54 x=-21
d.x-29-(-21)=-9
x-29+21=-9
x-29=-9-21
x-29=-30
x=-30+29
x=-1
1a) 25 .8 - 12.5 + 272 :17 - 8
= 200 - 60 + 16 - 8
= 140+16-8
= 156 - 8
= 148
b) 125: 25 +14 - 142 : 71
= 5 + 14 - 2
= 19 - 2 = 17
c) 13. 17 - 256: 16 + 14 : 7 - 1
= 221 - 16 + 2 - 1
= 205 + 2 - 1
= 207 - 1 = 206
d) 15 . 24 - 14 . 5 (145 : 5 - 27)
= 360 - 70 (29- 27)
= 360 - 70 . 2
= 360 - 140
= 220
2a) 37 + x = 55
x= 55 - 37
x = 18
b) x- 31 = 24
x = 24 + 31
x = 55
c) 21 (x-11) = 21
x - 11 = 21 : 21
x = 1 +11
x = 12
d ) 9. (x - 29)= 0
x - 29 = 0 :9
x = 29
e) (x - 1954) . 5 = 50
x - 1954 = 50 : 5
x = 1964
f ) 30 . 60 - x = 30
1800 - x = 30
x = 1800 - 30
x = 1770
Viết mỏi tay quá huhuh
a) 15 – ( 4 – x) = 6
=> 4 – x= 15 - 6
=> 4 – x= 9
=> x= 4 - 9
=> x= -5
Easy!
a) \(15-\left(4-x\right)=6\)
\(\Leftrightarrow4-x=15-6\)
\(\Leftrightarrow4-x=9\)
\(\Leftrightarrow x=4-9\)
\(\Leftrightarrow x=-5\)
Vậy \(x=-5\)
b) \(-30+\left(25-x\right)=-1\)
\(\Leftrightarrow\left(25-x\right)=-1-\left(-30\right)\)
\(\Leftrightarrow25-x=29\)
\(\Leftrightarrow x=25-29\)
\(\Leftrightarrow x=-4\)
c) \(x-\left(12-25\right)=-8\)
\(\Leftrightarrow x-\left(-13\right)=-8\)
\(\Leftrightarrow x=-8+-13\)
\(\Leftrightarrow x=-21\)
Vậy \(x=-21\)
d) \(\left(x-29\right)-\left(17-38\right)=-9\)
\(\Leftrightarrow\left(x-29\right)-\left(-21\right)=-9\)
\(\Leftrightarrow x-29=-9+\left(-21\right)\)
\(\Leftrightarrow x-29=-30\)
\(\Leftrightarrow x=-30+29\)
\(\Leftrightarrow x=-1\)
Vậy \(x=-1\)