HELPPPPPPPPPPPPPPPPPPPPP

Đáp án:m=$\frac{-13}{3}$ 

Giải thích các bước giải:

$\left \{ {{x-my=5-3m} \atop {mx-y=2}} \right.$

⇔$\left \{ {{x-my=5-3m} \atop {m²x-my=2m}} \right.$

⇔$\left \{ {{x-m²x=5-5m} \atop {mx-y=2}} \right.$

⇔$\left \{ {{x(m+1)=5} \atop {mx-y=2}} \right.$

⇔$\left \{ {{x=$\frac{5}{m+1}$ } \atop {$\frac{5m}{m+1}$-y=2}} \right.$

⇔$\left \{ {{x=$\frac{5}{m+1}$ } \atop {y=$\frac{5m}{m+1}$-2 }} \right.$

$\frac{5}{x}$+4=$\frac{3}{y}$ 

⇔$\frac{3}{y}$-$\frac{5}{x}$=4

⇔3:($\frac{5m}{m+1}$-2) - 5:($\frac{5m}{m+1}$)=4

⇔3:$\frac{3m-2}{m+1}$ - (m+1)=4

 ⇔$\frac{3m+3}{3m-2}$ - m-1=4

⇔1-$\frac{5}{3m-2}$ -m-1=4

⇔$\frac{5}{3m-2}$ -m=4

⇒m=$\frac{-13}{3}$