![](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)
a: Bạn ghi lại đề nha bạn
b: \(30\left(x+2\right)-6\left(x-5\right)-24x=100\)
=>\(30x+60-6x+30-24x=100\)
=>\(\left(30x-6x-24x\right)+\left(60+30\right)=100\)
=>0x=100-90=10(vô lý)
c: \(\left(x-7\right)\left(x+3\right)< 0\)
TH1: \(\left\{{}\begin{matrix}x-7>0\\x+3< 0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x>7\\x< -3\end{matrix}\right.\)
=>\(x\in\varnothing\)
TH2: \(\left\{{}\begin{matrix}x-7< 0\\x+3>0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x< 7\\x>-3\end{matrix}\right.\)
=>-3<x<7
mà x nguyên
nên \(x\in\left\{-2;-1;0;1;2;3;4;5;6\right\}\)
d: -1<2x-1<4
=>\(-1+1< 2x< 4+1\)
=>0<2x<5
=>0<x<2,5
mà x nguyên
nên \(x\in\left\{1;2\right\}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có: \(4.\left(\frac{1}{2}x+\frac{3}{4}\right)=\frac{3}{2}\)
\(\Rightarrow\frac{1}{x}x+\frac{3}{4}=\frac{3}{2}:4=\frac{3}{8}\)
\(\Rightarrow\frac{1}{2}x=\frac{3}{8}-\frac{3}{4}=\frac{-3}{8}\)
\(\Rightarrow x=\frac{-3}{8}:\frac{1}{2}=\frac{-3}{4}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(x+12\right)\left(x-3\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x+12=0\\x-3=0\end{cases}\Rightarrow\orbr{\begin{cases}x=-12\\x=3\end{cases}}}\)
\(\left(-x+5\right)\left(3-x\right)\)thiếu nha bn
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+20\right)=250\)
\(\Rightarrow20x+\left(1+2+3+...+20\right)=250\)
\(\Rightarrow20x+210=250\)
\(20x=250-210=40\)
\(x=40:20=2\)
\(x=2\)
![](https://rs.olm.vn/images/avt/0.png?1311)
3.|x-1|+2.|x-1|=3.|x-1|+4
3.|x-1|+2.|x-1|-3.|x-1|-4=0
3(x-1)+2(x-1)-3(x-1)-4=0
3x-3+2x-2-3x+3-4=0
2x-6=0
2x=6
x=3
#H
3.|x-1|+2.|x-1|=3.|x-1|+4.
=> 2.|x+1|=4 (bớt cả 2 vế cho 3.|x-1|
=>|x+1|=4:2
=>|x+1|=2
=>x+1= 2 hoặc x+1=-2
=>x=1 hoặc x=-3
vậy....