98 cong 98 =196
chuc ban hoc tot
\(\frac{31+m}{67+m}=\frac{3}{5}\)
\(\Leftrightarrow\)\(5.\left(31+m\right)=3.\left(67+m\right)\)
\(\Leftrightarrow\)\(155+5m=201+3m\)
\(\Leftrightarrow\)\(5m-3m=201-155\)
\(\Leftrightarrow\)\(2m=46\)
\(\Leftrightarrow\)\(m=23\)
TL
m=23
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