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Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời. c) pt <=> \(x-\frac{21}{5}=\frac{23}{7}< =>x=\frac{23}{7}+\frac{21}{5}=\frac{262}{35}\) vậy x = \(\frac{262}{35}\) d) \(x-\frac{3}{4}=\frac{51}{8}< =>x=\frac{51}{8}+\frac{3}{4}=\frac{57}{8}\) vậy x = \(\frac{57}{8}\) e) pt <=> \(\frac{7}{8}:x=\frac{7}{2}< =>\frac{7}{8}.\frac{1}{x}=\frac{7}{2}< =>\frac{7}{8x}=\frac{7}{2}< =>56x=14< =>x=\frac{14}{56}=\frac{1}{4}\) vậy x = \(\frac{1}{4}\) a) pt <=> \(x+\frac{11}{4}=\frac{17}{3}< =>x=\frac{17}{3}-\frac{11}{4}=\frac{35}{12}\) vậy x = \(\frac{35}{12}\) b) pt <=> \(\frac{x.7}{2}=\frac{19}{4}< =>x=\frac{19.2}{4.7}=\frac{38}{28}=\frac{19}{14}\) vậy x = \(\frac{19}{14}\) a) \(|x+1|=3\) \(\Rightarrow x+1=\pm3\) +) \(x+1=3\) +) \(x+1=-3\) \(\Rightarrow x=2\) \(\Rightarrow x=-4\) Vậy \(x\in\left\{2;-4\right\}\) b) \(3^2x+2^4=5^2\) \(9x+16=25\) \(9x=25-16\) \(9x=9\) \(x=1\) c) \(\frac{4+x}{7+y}=\frac{4}{7}\) \(\Rightarrow\left(4+x\right).7=\left(7+y\right).4\) \(\Rightarrow28+7x=28+4y\) \(\Rightarrow7x=4y\) Mà \(\left(7,4\right)=1\) và \(x+y=11\) Vậy \(x=4;y=7\) a) Ta có: \(\left|x+1\right|=3\) \(\Rightarrow x+1=\pm3\) Nếu x + 1 = 3 => x = 2 Nếu x + 1 = -3 => x = -4 Vậy x = {2;-4} b) \(3^2x+2^4=5^2\) \(\Rightarrow9x+16=25\) \(\Rightarrow9x=9\) \(\Rightarrow x=1\) Vậy x = 1 c) \(\frac{4+x}{7+x}=\frac{4}{7}\) \(\Rightarrow7\left(4+x\right)=4\left(7+x\right)\) \(\Rightarrow28+7x=28+4x\) \(\Rightarrow7x-4x=0\) \(\Rightarrow x=0\) Vậy x = 0 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) \(\frac{17}{2}-\left|2x-\frac{3}{4}\right|=-\frac{7}{4}\) \(\Rightarrow\left|2x-\frac{3}{4}\right|=\frac{17}{2}+\frac{7}{4}\) \(\Rightarrow\left|2x-\frac{3}{4}\right|=\frac{41}{4}\) \(\Rightarrow\left[\begin{array}{nghiempt}2x-\frac{3}{4}=\frac{41}{4}\\2x-\frac{3}{4}=-\frac{41}{4}\end{array}\right.\) \(\Rightarrow\left[\begin{array}{nghiempt}2x=11\\2x=-\frac{19}{2}\end{array}\right.\) \(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{11}{2}\\x=-\frac{19}{4}\end{array}\right.\) \(a,\)\(-\frac{3}{5}\cdot x=\frac{1}{4}+0,75\) \(-\frac{3}{5}\cdot x=\frac{1}{4}+\frac{3}{4}=\frac{4}{4}=1\) \(x=1\div\left(-\frac{3}{5}\right)\) \(x=-\frac{5}{3}\) \(b,\)\(\left(\frac{1}{7}-\frac{1}{3}\right)\cdot x=\frac{28}{5}\times\left(\frac{1}{4}-\frac{1}{7}\right)\) \(\left(\frac{3}{21}-\frac{7}{21}\right)\cdot x=\frac{28}{5}\cdot\left(\frac{7}{28}-\frac{4}{28}\right)\) \(-\frac{4}{21}\cdot x=\frac{28}{5}\cdot\frac{3}{28}\) \(-\frac{4}{21}\cdot x=\frac{3}{5}\) \(x=\frac{3}{5}\div\left(-\frac{4}{21}\right)\) \(x=-\frac{63}{20}\) \(c,\)\(\frac{5}{7}\cdot x=\frac{9}{8}-0,125\) \(\frac{5}{7}\cdot x=\frac{9}{8}-\frac{1}{8}\) \(\frac{5}{7}\cdot x=1\) \(x=1\div\frac{5}{7}\) \(x=\frac{7}{5}\) \(d,\)\(\left(\frac{2}{11}+\frac{1}{3}\right)\cdot x=\left(\frac{1}{7}-\frac{1}{8}\right)\cdot36\) \(\left(\frac{6}{33}+\frac{11}{33}\right)\cdot x=\left(\frac{8}{56}-\frac{7}{56}\right)\cdot36\) \(\frac{17}{33}\cdot x=\frac{1}{56}\cdot36\) \(\frac{17}{33}\cdot x=\frac{9}{14}\) \(x=\frac{9}{14}\div\frac{17}{33}\) \(x=\frac{9}{14}\cdot\frac{33}{17}=\frac{297}{238}\)
K
Khách
CM
Cao Minh Tâm
17 tháng 6 2018
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