Bài làm:
a) \(\frac{x}{3}=\frac{2}{3}+\left(-\frac{1}{7}\right)\)
<=>\(\frac{x}{3}=\frac{2.7-1.3}{3.7}\)
<=>\(\frac{x}{3}=\frac{11}{21}\)
<=> \(21.x=33\)
<=> \(x=\frac{11}{7}\)
b) \(x-\frac{1}{4}=\frac{2}{13}\)
<=> \(x=\frac{1}{4}+\frac{2}{13}\)
<=> \(x=\frac{13.1+2.4}{4.13}\)
<=> \(x=\frac{21}{52}\)
c)\(\frac{4}{7}.x=\frac{9}{8}-\frac{125}{1000}\)
<=> \(\frac{4}{7}.x=\frac{9}{8}-\frac{1}{8}\)
<=> \(\frac{4}{7}.x=\frac{8}{8}\)
<=> \(x=1:\frac{4}{7}\)
<=> \(x=\frac{7}{4}\)
Học tốt!!!!
7 + 67 + 56 - 76 + 368 - 93 + 45 -88 =
=? ? ? ? ? ? ?
= ? ? ? ? ?
= ?
a,\(\frac{x}{3}=\frac{2}{3}-\frac{1}{7}=\frac{11}{21}\)
\(< =>x.21=33< =>x=\frac{33}{21}\)
b,\(x-\frac{1}{4}=\frac{2}{13}\)
\(< =>x=\frac{2}{13}+\frac{1}{4}=\frac{21}{52}\)
c,\(\frac{4}{7}.x=\frac{9}{8}-\frac{125}{1000}=1\)
\(< =>x=1:\frac{4}{7}=\frac{7}{4}\)
Bài 1.
\(a)\)\(\frac{x}{3}=\frac{2}{3}+\frac{-1}{7}\)
\(\Leftrightarrow\frac{x}{3}=\frac{14}{21}+\frac{-3}{21}\)
\(\Leftrightarrow\frac{x}{3}=\frac{11}{21}\)
\(\Leftrightarrow21x=33\)
\(\Leftrightarrow x=\frac{11}{7}\)
Vậy\(x=\frac{11}{7}\)
\(b)\)\(x-\frac{1}{4}=\frac{2}{13}\)
\(\Leftrightarrow x=\frac{2}{13}+\frac{1}{4}\)
\(\Leftrightarrow x=\frac{8}{52}+\frac{13}{52}\)
\(\Leftrightarrow x=\frac{21}{52}\)
Vậy\(x=\frac{21}{52}\)
\(c)\)\(\frac{4}{7}x=\frac{9}{8}-\frac{125}{1000}\)
\(\Leftrightarrow\frac{4}{7}x=\frac{9}{8}-\frac{1}{8}\)
\(\Leftrightarrow\frac{4}{7}x=1\)
\(\Leftrightarrow x=\frac{7}{4}\)
Vậy\(x=\frac{7}{4}\)
Linz