Bài 12: Tìm x Î N) biết: a( x – 5)(x – 7) = 0 |
b) 541 + (218 – x) = 735 |
c) 96 – 3(x + 1) = 42 |
d) ( x – 47) – 115 = 0 | e) (x – 36):18 = 12 | g) (x – 3)(3 + x) = 0 |
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)
(x-5)(x-7)=0
=> x-5=0 hoặc x-7=0
=> x=5 hoặc x=7
541+(218-x)=735
=> 218-x=735-541
=> 218-x=194
=> x=218-194
=> x=24
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
(x-47)-115=0
=>x-47=0+115
=>x-47=115
=>x=115+47
=>x=162
(x-36):18=12
=>x-36=12.18
=>x-36=216
=>x=216+36
=>x=252
(x-5).(x-7)=0
x-5=0+7
x=7+5
x=12
541+(218-x)=735
218-x=735-541
x=218-196
x=12
96-3(x+1)=42
3(x+1)=96-42
x+1=54:3
x=17-1
x=16
(x-47)-115=0
x-47=0+115
x=115+47
x=162
(x-36):12=18
x-36=12*18
x-36=216
x=216+36
x=252
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 1254:253= (53)3: (52)3=59:56=53
b) 414:528=414: 52.14=414:(52)14= 414:2514
c) 12n:22n=
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a, 541 + ( 218 - x ) = 735
=> 218 - x = 735 - 541
=> 218 - x = 194
=> x = 218 - 194
=> x = 24
Vậy x = 24
b, 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
Vậy x = 17
c, ( x - 36 ) : 18 = 12
=> x - 36 = 12.18
=> x - 36 = 216
=> x = 216 + 36
=> x = 252
Vậy x = 252
d, 3x + 3x+1 + 3x+2 = 13.81
=> 3x.1 + 3x.3 + 3x.32= 13.81
=> 3x.( 1 + 3 + 32 ) = 13.81
=> 3x.( 1 + 3 + 9 ) = 13.81
=> 3x.13 = 13.81
=> 3x= 13.81:13
=> 3x= 81
=> 3x = 34
=> x = 4
Vậy x = 4
![](https://rs.olm.vn/images/avt/0.png?1311)
a )531 + ( 218 - x ) = 735
218 - x = 735 - 531
218 - x = 204
x = 218 - 204
x = 14
a ) 541 + ( 218 - x ) = 735
218 - x = 735 - 541
218 - x = 194
x = 218 - 194
x = 24
![](https://rs.olm.vn/images/avt/0.png?1311)
a) Ta có: 541 + (218-x) = 735
=> 218 -x = 735 - 541
=> 218 - x = 194
=> x = 218 - 194
=>x = 16
b;c làm tưởng tự
![](https://rs.olm.vn/images/avt/0.png?1311)
575- [6x+70] = 445 315 +[125-x] = 435 f 541+[218-x]=435
6x+70 =575-445 125-x = 435- 315 218-x = 541-435
6x+70 = 130 125-x =120 218-x =106
6x = 130-70 x = 125 - 120 x = 218-106
6x = 60 x = 5 x = 112
x = 60:6
x = 10
bạn ơi khó hiểu quá,.,.,.
\(\orbr{\begin{cases}\\\end{cases}}\)
\(a,\left(x-5\right)\left(x-7\right)=0\Leftrightarrow\orbr{\begin{cases}x-5=0\\x-7=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=5\\x=7\end{cases}}}\)
\(b,541+\left(218-x\right)=735\Leftrightarrow218-x=194\Leftrightarrow x=24\)
\(c,96-3\left(x+1\right)=42\Leftrightarrow3\left(x+1\right)=54\Leftrightarrow x+1=18\Leftrightarrow x=17\)
\(d,\left(x-47\right)-115=0\Leftrightarrow x-47=115\Leftrightarrow x=162\)
\(e,\left(x-36\right):18=12\Leftrightarrow x-36=216\Leftrightarrow x=252\)
g giống a
a) \(\left(x-5\right)\left(x-7\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-5=0\\x-7=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=5\\x=7\end{cases}}\)
Vậy \(x\in\left\{5;7\right\}\)
b) \(541+\left(218-x\right)=735\)
\(\Rightarrow541+218-x=735\)
\(\Rightarrow-x=-24\)
\(\Rightarrow x=24\)
Vậy \(x=24\)
c) \(96-3\left(x+1\right)=42\)
\(\Rightarrow96-3x-3=42\)
\(\Rightarrow-3x=-51\)
\(\Rightarrow x=17\)
Vậy \(x=17\)
d) \(\left(x-47\right)-115=0\)
\(\Rightarrow x-47-115=0\)
\(\Rightarrow x-162=0\)
\(\Rightarrow x=162\)
Vậy \(x=162\)
e) \(\left(x-36\right):18=12\)
\(\Rightarrow x-36=216\)
\(\Rightarrow x=252\)
Vậy \(x=252\)
g) \(\left(x-3\right)\left(3+x\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-3=0\\3+x=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)
Vậy \(x\in\left\{3;-3\right\}\)