@FanRapital
Đáp án:
Thay ( x , y )= ( 1 , 5 ) vào hệ pt ta được :
$\left \{ {{3.a.1-(b+1).5=93} \atop {1.b+4.a.5=-3}} \right.$
=> $\left \{ {{3a-5b=98} \atop {20a+b=-3}} \right.$
=> $\left \{ {{3a-5b=98} \atop {100a+5b=-15}} \right.$
=> $\left \{ {{103a=83} \atop {3a-5b=98}} \right.$
=> $\left \{ {{a=\frac{83}{103} } \atop {3.\frac{83}{103} -5b=98}} \right.$
=> $\left \{ {{a=\frac{83}{103} } \atop {b=\frac{-1969}{103} }} \right.$
Vậy a = $\frac{83}{103}$ , b = $\frac{-1969}{103}$
