[tex]x-\ first\ number\\y-\ second\ number\\\\
\left \{ {{x+y=19} \atop {xy=48}} \right. \\\\ \left \{ {{x=19-y} \atop {xy=48}} \right. \\\\substitution\ method\\\\
(19-y)y=48\\\\
19y-y^2-48=0\\\\
-y^2+19y-48=0\\\\Factorisation:\\
-(y^2-3y-16y+48)=0\\\\
-(y-16)(y-3)=0\\\\
y=16\ \ \ or\ \ \ y=3\\\\
x=3\ \ \ or\ \ \ x=16\\\\Numbers\ are:\ 3\ and\ 16.[/tex]
