\(\frac{31}{100}.x=372\Leftrightarrow x=372:\frac{31}{100}=1200\)

HT

\(\frac{11}{3}.x=-286\Leftrightarrow x=\left(-286\right):\frac{11}{3}=-78\)

HT

TL

\(\frac{11}{3}x=-286\)

\(\Leftrightarrow x=-286:\frac{11}{3}\)

     \(\Leftrightarrow x=-78\)

HT

ta có 17/-35=-17/35
(3/17+14/17)+(-5/13+-8/13)+(-18/35+-17/35)
=17/17+-17/17+-35/35
=1+-1+-1
=-1

\(\frac{1}{5}-\frac{-2}{3}-\frac{7}{10}=\)

\(\frac{1.6}{5.6}-\frac{(-2).10}{3.10}-\frac{7.3}{10.3}\)

= \(\frac{6}{30}-\frac{-20}{30}-\frac{21}{30}\)

= \(\frac{6}{30}+\frac{20}{30}-\frac{21}{30}\)

=\(\frac{6+20-21}{30}\)

= \(\frac{5}{30}\)

= \(\frac{1}{6}\)

HTTT

I don't know 

3/17 + -5/13 + -18/35 + 14/17 + 17/-35 + -8/13=-1

\(\frac{2}{20}+\frac{2}{30}+\frac{2}{42}+\frac{2}{56}+\frac{2}{72}+\frac{2}{90}\)

\(=\frac{2}{4\times5}+\frac{2}{5\times6}+\frac{2}{6\times7}+\frac{2}{7\times8}+\frac{2}{8\times9}+\frac{2}{9\times10}\)

\(=2\left(\frac{1}{4\times5}+\frac{1}{5\times6}+\frac{1}{6\times7}+\frac{1}{7\times8}+\frac{1}{8\times9}+\frac{1}{9\times10}\right)\)

\(=2\left(\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}\right)\)

\(=2\left(\frac{1}{4}-\frac{1}{10}\right)=\frac{3}{10}\)

3/10 nha!

     Học tốt!

x=1 nhé

<=> -3 = -375(x + 3/5)

<=> x = -74/125