![](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)
Ta có: \(x+18954\div3^5=4.5^3\)
\(\Leftrightarrow x+18954\div243=4.125\)
\(\Leftrightarrow x+78=500\)
\(\Rightarrow x=422\)
x + 18954 : 35 = 4 . 53
=> x + 18954 : 243 = 4 . 125
=> x + 78 = 500
=> x = 422
Vậy x = 422
![](https://rs.olm.vn/images/avt/0.png?1311)
a) (3x - 72) . 59 = 4.510
=> 3x - 49 = 4.5
=> 3x - 49 = 20
=> 3x = 69
=> x = 23
Vậy x = 23
b) 210 < 7x < 280
=> 30 < x < 40
mà x \(\inℕ\)
=> \(x\in\left\{31;32;33;34;35;36;37;38;39\right\}\)
c) x + 2 \(⋮\)x - 1
=> x - 1 + 3 \(⋮\)x - 1
Nhận thấy x - 1 \(⋮\)x - 1
=> 3 \(⋮\)x - 1
=> x - 1 \(\inƯ\left(3\right)=\left\{1;-1;3;-3\right\}\)
=> \(x\in\left\{1;0;4;-2\right\}\)
mà x \(\inℕ\Rightarrow x\in\left\{1;0;4\right\}\)
d) 2x + 7 \(⋮\)x + 1
=> 2(x + 1) + 5 \(⋮\)x + 1
Nhận thấy 2(x + 1) \(⋮\)x + 1
=> 5 \(⋮\)x + 1
=> x + 1 \(\inƯ\left(5\right)=\left\{1;-1;5;-5\right\}\)
=> \(x\in\left\{0;4\right\}\)(vì x là số tự nhiên)
b) 210 < 7x < 280
\(\Rightarrow\)7x\(\in\){ 211; 212; 213; .................; 279 }
Vì cứ cách 7 đơn vị thì có 1 số chia hết cho 7
\(\Rightarrow\)7x = 217; 224; 231; 238; 245; 252; 259; 266; 273
( Còn đâu x bạn tự tính nhé )
![](https://rs.olm.vn/images/avt/0.png?1311)
(1/3-1/4+1/4-1/5+1/5-.......+1/x.(x+1)=3/10
1/3-1/x+1=3/10
tự làm...
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
(3x - 72) . 59 = 4.510
(3x - 72) = 4.510 : 59
3x - 72 = 4.5
3x - 72 = 20
3x = 20 + 72
3x = 69
x = 23
![](https://rs.olm.vn/images/avt/0.png?1311)
3.(1/4.5+1/5.6+...+1/9.10).x=9/2
3.(1/4-1/5+1/5-1/6+...+1/9-1/10).x=9/2
3.(1/4-1/10).x=9/2
3.3/20.x=9/2
9/20.x=9/2
x=9/2:9/20
x=10
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 7.(x-5) +2 = 51
=> 7.(x-5) = 49
=> x-5 = 7
=> x= 12
b)\(\left(4^3-11.x\right).5^3=4.5^4\)
\(\Rightarrow\left(64-11.x\right).125=2500\)
\(\Rightarrow64-11.x=20\)
\(\Rightarrow11.x=44\)
\(\Rightarrow x=4\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(4^3-11x\right).5^3=4.5^4\)
\(\Rightarrow\left(4^3-11x\right)=4.5^4\div5^3\)
\(\Rightarrow4^3-11x=20\)
\(\Rightarrow11x=4^3-20\)
\(\Rightarrow11x=44\)
\(\Rightarrow x=4\)
(43 - 11 . x) . 53 = 4 . 54 = 2500
(43 - 11 . x) = 2500 : 125
43 - 11 . x = 20
11 . x = 43 - 20
11 . x = 44
x = 44 : 11
x = 4
Học tốt!!!
\(x+18954:3^5=4.5^3\)
\(x+78=500\)
\(x=500-78\)
\(x=422\)
Vậy x = 422 .