Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
d: =>-x-5/6=7/12-4/12=3/12=1/4
=>-x=1/4+5/6=13/12
hay x=-13/12
e: =>x+3=-5
hay x=-8
f: =>4,5-2x=-1/2
=>2x=5
hay x=5/2
a) (x + 1/2) . (2/3 − 2x) = 0
\(\Rightarrow\left[\begin{array}{nghiempt}x+\frac{1}{2}=0\\\frac{2}{3}-2x=0\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\2x=\frac{2}{3}\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\x=\frac{1}{3}\end{array}\right.\)
b) \(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)
\(\Rightarrow\left(x.\frac{44}{7}+\frac{3}{7}\right).\frac{11}{5}=-2+\frac{3}{7}\)
\(\Rightarrow\left(x.\frac{44}{7}+\frac{3}{7}\right).\frac{11}{5}=-\frac{11}{7}\)
\(\Rightarrow x.\frac{44}{7}+\frac{3}{7}=-\frac{11}{7}:\frac{11}{5}=-\frac{11}{7}.\frac{5}{11}\)
\(\Rightarrow x.\frac{44}{7}+\frac{3}{7}=-\frac{5}{7}\)
\(\Rightarrow x.\frac{44}{7}=-\frac{5}{7}-\frac{3}{7}\)
\(\Rightarrow x.\frac{44}{7}=-\frac{8}{7}\)
\(\Rightarrow x=-\frac{8}{7}:\frac{44}{7}=-\frac{8}{7}.\frac{7}{44}\)
\(\Rightarrow x=-\frac{2}{11}\)
c) \(x.3\frac{1}{4}+\left(-\frac{7}{6}\right).x-1\frac{2}{3}=\frac{5}{12}\)
\(\Rightarrow x\left(3\frac{1}{4}-\frac{7}{6}\right)=\frac{5}{12}+\frac{5}{3}\)
\(\Rightarrow x\left(\frac{13}{4}-\frac{7}{6}\right)=\frac{25}{12}\)
\(\Rightarrow x.\frac{25}{12}=\frac{25}{12}\)
\(\Rightarrow x=\frac{25}{12}:\frac{25}{12}\)
\(\Rightarrow x=1\)
d) \(5\frac{8}{17}:x+\left(-\frac{4}{17}\right):x+3\frac{1}{7}:17\frac{1}{3}=\frac{4}{11}\)
\(\Rightarrow\left(5\frac{8}{17}-\frac{4}{17}\right):x+\frac{22}{7}:\frac{52}{3}=\frac{4}{11}\)
\(\Rightarrow5\frac{4}{17}:x+\frac{33}{182}=\frac{4}{11}\)
\(\Rightarrow\frac{89}{17}:x=\frac{4}{11}-\frac{33}{182}\)
\(\Rightarrow\frac{89}{17}:x=\frac{365}{2002}\)
\(\Rightarrow x=\frac{89}{17}:\frac{365}{2002}\)
\(\Rightarrow x\approx28,7\) (số hơi lẻ)
e) \(\frac{17}{2}-\left|2x-\frac{3}{4}\right|=-\frac{7}{4}\)
\(\Rightarrow\left|2x-\frac{3}{4}\right|=\frac{17}{2}+\frac{7}{4}\)
\(\Rightarrow\left|2x-\frac{3}{4}\right|=\frac{41}{4}\)
\(\Rightarrow\left[\begin{array}{nghiempt}2x-\frac{3}{4}=\frac{41}{4}\\2x-\frac{3}{4}=-\frac{41}{4}\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}2x=11\\2x=-\frac{19}{2}\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{11}{2}\\x=-\frac{19}{4}\end{array}\right.\)
\(a)\) \(\left(2x+1\right)\left(2x-3\right)=7\)
Có \(4\) trường hợp :
\(\Leftrightarrow\)\(\hept{\begin{cases}2x+1=1\\2x-3=7\end{cases}\Leftrightarrow\hept{\begin{cases}2x=0\\2x=10\end{cases}\Leftrightarrow}\hept{\begin{cases}x=0\\x=5\end{cases}}}\)
\(\Leftrightarrow\)\(\hept{\begin{cases}2x+1=-1\\2x-3=-7\end{cases}\Leftrightarrow\hept{\begin{cases}2x=-2\\2x=-4\end{cases}\Leftrightarrow}\hept{\begin{cases}x=-1\\x=-2\end{cases}}}\)
\(\Leftrightarrow\)\(\hept{\begin{cases}2x+1=7\\2x-3=1\end{cases}\Leftrightarrow\hept{\begin{cases}2x=6\\2x=4\end{cases}\Leftrightarrow}\hept{\begin{cases}x=3\\x=2\end{cases}}}\)
\(\Leftrightarrow\)\(\hept{\begin{cases}2x+1=-7\\2x-3=-1\end{cases}\Leftrightarrow\hept{\begin{cases}2x=-8\\2x=2\end{cases}\Leftrightarrow}\hept{\begin{cases}x=-4\\x=1\end{cases}}}\)
Vậy không có giá trị nào của x thoả mãn đề bài
\(b)\) \(x\left(x-7\right)+3\left(x-7\right)=11\)
\(\Leftrightarrow\)\(\left(x+3\right)\left(x-7\right)=11\)
Có \(4\) trường hợp :
\(\Leftrightarrow\)\(\hept{\begin{cases}x+3=1\\x-7=11\end{cases}\Leftrightarrow\hept{\begin{cases}x=-2\\x=18\end{cases}}}\)
\(\Leftrightarrow\)\(\hept{\begin{cases}x+3=-1\\x-7=-11\end{cases}\Leftrightarrow\hept{\begin{cases}x=-4\\x=-4\end{cases}}}\)
\(\Leftrightarrow\)\(\hept{\begin{cases}x+3=11\\x-7=1\end{cases}\Leftrightarrow\hept{\begin{cases}x=8\\x=8\end{cases}}}\)
\(\Leftrightarrow\)\(\hept{\begin{cases}x+3=-11\\x-7=-1\end{cases}\Leftrightarrow\hept{\begin{cases}x=-14\\x=6\end{cases}}}\)
Vậy \(x\in\left\{-4;8\right\}\)