[tex]\displaystyle\bf\\\left \{ {{11x+3y=39 \ |\cdot 2} \atop {3x-2y=5 \ |\cdot 3}} \right. \\\\\\+\left \{ {{22x+6y=78} \atop {9x-6y=15}} \right. \\----------\\22x+6y+9x-6y=78+15\\\\31x=93\\\\x=93:31=3\\\\2y=3x-5=3\cdot 3-5=9-5=4\\\\y=4:2=2\\\\\\Otvet \ : \ (3 \ ; \ 4)[/tex]