[latex] \left \{ {{ \frac{3a+1}{5} +\frac{2b-1}{3} = \frac{2}{5} } \atop { \frac{3a-2}{2} + \frac{b-3}{4} =1}} \right. [/latex] срочнооооо

[latex]\begin{cases}\frac{3a+1}5+\frac{2b-1}3=\frac25\;\;\;\;\;\times15\\\frac{3a-2}2+\frac{b-3}4=1\;\;\;\;\;\;\;\times4\end{cases}\Rightarrow\begin{cases}9a+3+10b-5=6\\6a-4+b-3=4\end{cases}\Rightarrow\\\Rightarrow\begin{cases}9a+10(11-6a)=8\\b=11-6a\end{cases}\\9a+10(11-6a)=8\\9a+110-60a=8\\51a=102\\a=2\\\begin{cases}a=2\\b=-1\end{cases}[/latex]