Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Chị gái xinh đẹp à. Câu hỏi của chị khó quá ko ai trả lời. Thôi thì.......k cho mem đi😉
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 \(x\in\left\{1;2\right\}\)
\(a,\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}+\dfrac{5}{7}=9\dfrac{5}{7}\)
\(\Leftrightarrow\left(x-\dfrac{1}{2}\right).3=\dfrac{68}{7}-\dfrac{5}{7}\)
\(\Leftrightarrow\left(x-\dfrac{1}{2}\right).3=9\)
\(\Leftrightarrow x-\dfrac{1}{3}=3\)
\(\Leftrightarrow x=3+\dfrac{1}{3}\)
\(\Leftrightarrow x=\dfrac{9}{3}+\dfrac{1}{3}\)
\(\Leftrightarrow x=\dfrac{10}{3}\)
\(b,x+30\%x=-1,31\)
\(\Leftrightarrow x+\dfrac{3}{10}.x=-\dfrac{131}{100}\)
\(\Leftrightarrow x.\left(1+\dfrac{3}{10}\right)=-\dfrac{131}{100}\)
\(\Leftrightarrow x.\dfrac{13}{10}=-\dfrac{131}{100}\)
\(\Leftrightarrow x=-\dfrac{131}{100}.\dfrac{10}{13}\)
\(\Leftrightarrow x=-\dfrac{131}{130}\)
\(c,-\dfrac{2}{3}x+\dfrac{1}{5}=\dfrac{1}{10}\)
\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{1}{10}-\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{1}{10}-\dfrac{2}{10}\)
\(\Leftrightarrow-\dfrac{2}{3}x=-\dfrac{1}{10}\)
\(\Leftrightarrow x=-\dfrac{1}{10}.\left(-\dfrac{3}{2}\right)\)
\(\Leftrightarrow x=\dfrac{3}{20}\)
nhiều quá :((
\(a,2\left(x-5\right)-3\left(x+7\right)=14\)
\(2x-10-3x-21=14\)
\(-x-31=14\)
\(-x=45\)
\(x=45\)
\(b,5\left(x-6\right)-2\left(x+3\right)=12\)
\(5x-30-2x-6=12\)
\(3x-36==12\)
\(3x=48\)
\(x=16\)
\(c,3\left(x-4\right)-\left(8-x\right)=12\)
\(3x-12-8+x=0\)
\(4x-20=0\)
\(4x=20\)
\(x=5\)
Cố nốt nha bn !
cảm ơn, bn nha:)))
mà hình như bạn TOP 3 trả lời câu hỏi pải ko nhỉ???
-12.(x - 5) + 7.(3 - x) = 5
-12x + 60 + 21 - 7x = 5
-12x - 7x = 5 - 60 - 21
-19x = -76
x = -76 : (-19)
x = 4
Vậy x = 4
a)|2x-5|=13
2x-5=13=>x=9
2x-5=-13=>x=-4
b)3|x+1|+1=28
3|x+1|=28-1
3|x+1|=27
|x+1|=27:3
|x+1|=9
x+1=9=>x=8
x+1=-9=>x=-10
tick nha
a)(x+1)+(x+3)+...+(x+97)+(x+99)=0
x.50+2500=0
x.50=0-2500
x.50=-2500
x=-2500:5
x=-500
1) \(x.\left(x+7\right)=0\)
\(=>\left[\begin{matrix}x=0\\x+7=0\end{matrix}\right.=>\left[\begin{matrix}x=0\\x=-7\end{matrix}\right.\)
2) \(\left(x+12\right).\left(x-3\right)=0\)
\(=>\left[\begin{matrix}x+12=0\\x-3=0\end{matrix}\right.=>\left[\begin{matrix}x=-12\\x=3\end{matrix}\right.\)
3) \(\left(-x+5\right).\left(3-x\right)=0\)
\(=>\left[\begin{matrix}-x+5=0\\3-x=0\end{matrix}\right.=>\left[\begin{matrix}x=5\\x=3\end{matrix}\right.\)
4) \(x.\left(2+x\right).\left(7-x\right)=0\)
\(=>\left[\begin{matrix}x=0\\2+x=0\\7-x=0\end{matrix}\right.=>\left[\begin{matrix}x=0\\x=-2\\x=7\end{matrix}\right.\)
5) \(\left(x-1\right).\left(x+2\right).\left(-x-3\right)=0\)
\(=>\left[\begin{matrix}x-1=0\\x+2=0\\-x-3=0\end{matrix}\right.=>\left[\begin{matrix}x=1\\x=-2\\x=-3\end{matrix}\right.\)
a, b: ở trên.
c. (x+1)+(x+3)+...+(x+97)+(x+99)=0 (có 50 cặp)
=> x+1+x+3+...+x+97+x+99 = 0
=> (x+x+...+x)+(1+3+...+97+99)=0
=> 50x+\(\frac{\left(99+1\right).50}{2}\)=0
=> 50x+2500=0
=> 50x=-2500
=> x=-2500:50
=> x=-50