/x-3/-3=-x giúp mik nha! mai thầy mik kiểm tra rùi:))
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\(\left(3\frac{1}{2}+2x\right).2\frac{2}{3}=5\frac{1}{3}\)
<=>\(\left(\frac{7}{2}+2x\right).\frac{8}{3}=\frac{16}{3}\)
<=>\(\frac{28}{3}+\frac{16x}{3}=\frac{16}{3}\)
<=>\(\frac{16x}{3}=\frac{-2}{3}\)
<=>\(16x=-2\)
<=>\(x=\frac{-1}{8}\)
vậy \(x=\frac{-1}{8}\)
b,\(\left|2x+3\right|=5\)
xét x<0,ta co: \(\left|2x+3\right|=5\)<=> \(-2x+3=5\)<=>\(-2x=2\)<=>\(x=-1\)(loại)
xét x>0,ta co:\(\left|2x+3\right|=5\)<=>\(2x+3=5\)<=>\(2x=2\)<=>\(x=1\)
c,\(\frac{x-2}{4}=\frac{5+x}{3}\)
<=>\(\frac{3x-6}{12}=\frac{20+4x}{12}\)
=>\(3x-6=20+4x\)
<=>\(3x-6-20-4x=0\)
<=>\(-x-26=0\)
<=>\(-x=26\)
<=>\(x=-26\)
kl:.......
Thu dạ nguyên tiêu nguyệt chính viên,
Xuân giang xuân Thủy tiếp xuân thiên.
Yên ba thâm xứ đàm quân sự,
Dạ bán quy lai nguyệt mãn thuyền.
Sông xuân nước lẫn màu trời thêm xuân.
Giữa dòng bàn bạc việc quân,
Khuya về bát ngát trăng ngân đầy thuyền.
\(\dfrac{x-1}{x}-\dfrac{1}{x+1}=\dfrac{2x-1}{x^2+x}\)
\(\Leftrightarrow\dfrac{x-1}{x}-\dfrac{1}{x+1}=\dfrac{2x-1}{x\left(x+1\right)}\)
ĐKXĐ : \(\left\{{}\begin{matrix}x\ne0\\x+1\ne0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ne0\\x\ne-1\end{matrix}\right.\)
Ta có : `(x-1)/x -1/(x+1) =(2x-1)/(x(x+1))`
\(\Leftrightarrow\dfrac{\left(x-1\right)\left(x+1\right)}{x\left(x+1\right)}-\dfrac{x}{x\left(x+1\right)}=\dfrac{2x-1}{x\left(x+1\right)}\)
`=> x^2 +x -x-1 -x-2x+1=0`
`<=> x^2 -3x =0`
`<=> x(x-3)=0`
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(ktm\right)\\x=3\end{matrix}\right.\)
__
`(x+2)(5-3x)=0`
\(\Leftrightarrow\left[{}\begin{matrix}x+2=0\\5-3x=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\3x=5\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=\dfrac{5}{3}\end{matrix}\right.\)
__
\(\dfrac{5\left(1-2x\right)}{3}+\dfrac{x}{2}=\dfrac{3\left(x-5\right)}{4}-2\)
\(\Leftrightarrow\dfrac{20\left(1-2x\right)}{12}+\dfrac{6x}{12}=\dfrac{9\left(x-5\right)}{12}-\dfrac{24}{12}\)
`<=> 2x- 40x + 6x = 9x - 45 -24`
`<=> 2x- 40x + 6x-9x + 45 +24=0`
`<=>-41x+69=0`
`<=>-41x=-69`
`<=> x=69/41`
\(\left(-24\right):\left(2-x\right)=6\)
\(\left(2-x\right)=\left(-24\right):6\)
\(\left(2-x\right)=-4\)
\(x=2-\left(-4\right)\)
\(x=6\)
(-24) :(2-x) =6
2-x = 6 x (-24)
2-x= -146
x = 2- (-146)
Vậy x = 146
a:=>x^2-1-x=2x-1
=>x^2-x-1=2x-1
=>x^2-3x=0
=>x=0(loại) hoặc x=3(nhận)
b:=>x+2=0 hoặc 5-3x=0
=>x=-2 hoặc x=5/3
c:=>20(1-2x)+6x=9(x-5)-24
=>20-40x+6x=9x-45-24
=>-34x+20=9x-69
=>-43x=-89
=>x=89/43
d: =>x^2+4x+4-x^2-2x+3=2x^2+8x-4x-16-3
=>2x^2+4x-19=-2x+7
=>2x^2+6x-26=0
=>x^2+3x-13=0
=>\(x=\dfrac{-3\pm\sqrt{61}}{2}\)
e: =>(2x-3)(2x-3-x-1)=0
=>(2x-3)(x-4)=0
=>x=4 hoặc x=3/2
a) \(\frac{x}{3}\)\(-\)\(\frac{1}{8}\)\(=\)\(\frac{5}{8}\)
\(\Rightarrow\) \(\frac{x}{3}\)=\(\frac{5}{8}+\frac{1}{8}\)
\(\Rightarrow\) \(\frac{x}{3}\)\(=\frac{3}{4}\)
\(\Rightarrow\) x=3.3:4
\(\Rightarrow\) x=2,25
Vậy x=2,25
b) \(3\frac{1}{3}\).x-\(6\frac{3}{4}=3\frac{1}{4}\)
\(\Rightarrow\)\(\frac{10}{3}\).x-\(\frac{27}{4}=\frac{13}{4}\)
\(\Rightarrow\) \(\frac{10}{3}\).x=\(\frac{13}{4}+\frac{27}{4}\)
\(\Rightarrow\) \(\frac{10}{3}\).x=10
\(\Rightarrow\) x=\(10\div\frac{10}{3}\)
\(\Rightarrow\) x=3
Vậy x=3
Ủng hộ mik nha mọi người !
Ta có : \(\frac{x}{3}-\frac{1}{8}=\frac{5}{8}\)
\(\Leftrightarrow\frac{x}{3}=\frac{5}{8}-\frac{1}{8}\)
\(\Leftrightarrow\frac{x}{3}=\frac{1}{2}\)
\(\Leftrightarrow x=\frac{1}{2}.\frac{1}{3}=\frac{1}{6}\)
bai 1
\(\frac{7}{4}\)+ \(\frac{5}{6}\):5 - 0,375.2.\(^{\left(-2\right)^2}\)= \(\frac{7}{4}\)+ \(\frac{5}{6}\)x\(\frac{1}{5}\)- \(\frac{15}{4}\). 2.4=\(\frac{7}{4}\)+\(\frac{1}{6}\)-\(\frac{15}{4}\).8=\(\frac{42}{24}\)+\(\frac{4}{24}\)-30=\(\frac{11}{6}\)-30=-169/6
\(\frac{1}{4}\)+\(\frac{3}{4}\). \(\left(\frac{-1}{2}+\frac{2}{3}\right)\)=\(\frac{1}{4}\)+ \(\frac{3}{4}\).\(\left(\frac{-3}{6}+\frac{4}{6}\right)\)= \(\frac{1}{4}+\frac{3}{4}.\frac{1}{6}=\frac{1}{4}+\frac{3}{8}\)= \(\frac{5}{8}\)
| x - 3 | - 3 = -x
⇔| x - 3 | = -x + 3
⇔| x - 3 | = -(x - 3)
Vì |x - 3| ≥ 0 nên
⇒ -(x - 3) ≥ 0
⇒ x - 3 ≤ 0
⇒x ≤ -3
cám ơn nha !:))