![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
`@` `\text {Ans}`
`\downarrow`
`a,`
`x - 280 \div 35 = 554`
`=> x - 8 = 554`
`=> x = 554 + 8`
`=> x = 562`
Vậy, `x = 562`
`b,`
`x + (5 \div 3) = 500`
`=> x + 5/3 = 500`
`=> x = 500 - 5/3`
`=> x = 1495/3`
Vậy, `x = 1495/3`
`c,`
`390 \div (5x - 5) = 39`
`=> 5x - 5 = 390 \div 39`
`=> 5x - 5 = 10`
`=> 5x = 10 + 5`
`=> 5x = 15`
`=> x = 15 \div 5`
`=> x = 3`
Vậy, `x = 3`
`d,`
`34x - 14x = 200`
`=> (34 - 14)x = 200`
`=> 20x = 200`
`=> x = 200 \div 20`
`=> x = 10`
Vậy, `x = 10.`
`@` `\text {Kaizuu lv uuu}`
a) \(x-280:35=554\)
\(x-8=554\)
\(x=562\)
b) \(x+\left(5:3\right)=500\)
\(x+\dfrac{5}{3}=500\)
\(x=500-\dfrac{5}{3}=\dfrac{1500}{3}-\dfrac{5}{3}=\dfrac{1495}{3}\)
c) \(390:\left(5x-5\right)=39\)
\(5x-5=\dfrac{39}{390}=\dfrac{1}{10}\)
\(5x=5+\dfrac{1}{10}\)
\(5x=\dfrac{51}{10}\)
\(x=\dfrac{51}{10}.\dfrac{1}{5}=\dfrac{51}{50}\)
d) \(34x-14x=200\)
\(20x=200\)
\(x=200:20=10\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a, 71.2 – 6.(2x+5) = 10 5 : 10 3
71.2 – 6.(2x+5) = 10 2
6.(2x+5) = 71.2 – 100
6.(2x+5) = 42
x = 1
b, 5 x + 3 4 . 6 8 = 6 9 . 3 4
5 x + 3 4 . 6 8 = 6 8 . 6 . 3 4
5 x + 3 4 = 6 8 . 6 . 3 4 : 6 8 = 6 . 3 4
5x = 6 . 3 4 - 3 4 = 5 . 3 4
x = 3 4
c, 12:{390:[5. 10 2 – ( 5 3 + x . 7 2 )]} = 4
390:[5. 10 2 – ( 5 3 + x . 7 2 )] = 12:4 = 3
5. 10 2 – ( 5 3 + x . 7 2 ) = 390:3 = 130
5 3 + x . 7 2 = 5. 10 2 – 130 = 370
x . 7 2 = 370 – 5 3 = 245
x = 245: 7 2 = 5
d, 5 3 .(3x+2):13 = 10 3 : 13 5 : 13 4
5 3 .(3x+2):13 = 10 3 : 13
3x+2 = 10 3 : 13 : 5 3 .13 = 8
x = 2
![](https://rs.olm.vn/images/avt/0.png?1311)
720 : [ 41 - (2\(x\) - 5)] = 22.5
41 - (2\(x\) - 5) = 720 :110
2\(x\) - 5 = 41 - \(\dfrac{72}{11}\)
2\(x\) - 5 = \(\dfrac{379}{11}\)
2\(x\) = \(\dfrac{379}{11}\) + 5
2\(x\) = \(\dfrac{434}{11}\)
\(x\) = \(\dfrac{434}{11}\) : 2
\(x\) = \(\dfrac{217}{11}\)
15 - \(x\) = 7 - (-2)
15 - \(x\) = 7 + 2
15 - \(x\) = 9
\(x\) = 15 - 9
\(x\) = 6
![](https://rs.olm.vn/images/avt/0.png?1311)
a,71.2-6.(2x+5)=10^5:10^3
142-6.(2x+5)=10^2
142-6.(2x+5)=100
6.(2x+5)=142-100
6.(2x+5)=42
2x+5=42:6
2x+5=7
2x=7-5
2x=2
x=1
Vậy x=1
![](https://rs.olm.vn/images/avt/0.png?1311)
a) x = 2.
b) x = 7.
c) x= 12.
d) x= 45.
e) x = 18.
f) x = 10.
![](https://rs.olm.vn/images/avt/0.png?1311)
(6x-39):3=201
6x-39=201.3
6x-39=603
6x=603+39
6x=642
x=107
23+5x=5^3
23+5x=125
5x=125-23
5x=102
x=102:5
x=20,4
![](https://rs.olm.vn/images/avt/0.png?1311)
Theo đề bài ta có:
268 - 18 ⋮ X = 250 ⋮ X
390 - 40 ⋮ X = 350 ⋮ X
Hay X là ƯC(250,350)
⇒ X ϵ ƯCLN(250,350)
Ta có: 250 = 2.53
350 = 2. 52. 7
⇒ ƯCLN(250,350) = 2. 52 = 50
⇒ 50 ⋮ X
⇒ X ϵ {1; 2; 5; 10; 25; 50}
268:x dư 18 => 250 chia hết cho x
390:x dư 40 => 350 chia hết cho x
\(250=5^3.2;350=5^2.2.7\\ ƯCLN\left(250;350\right)=5^2.2=50\\ x\inƯ\left(50\right)=\left\{1;2;5;10;25;50\right\}\)
Vì 390:x dư 40 => x>40
Vậy: x=50
\(\dfrac{390}{5x-5}=39\left(ĐK:x\ne1\right)\)
<=> \(5x-5=10\)
<=> \(5x=15\)
<=> \(x=3\left(TM\right)\)
(Mik viết ra phân số luôn cho gọn nhé.)
390 : ( 5x - 5 ) = 39
5x - 5 =390:39
5x - 5 =10
5x =10-5
5x = 5
x =5:5
x =1
Vậy x=1