[tex]\displaystyle\bf\\\left \{ {{3x + 2y = 5 \: \: | \times 4} \atop { - 4x + 3y = 16 \: \: | \times 3 }} \right. \\ \displaystyle\bf\\ + \left \{ {{12x + 8y = 20} \atop { - 12x + 9y = 48 }} \right. \\ \\8y + 9y = 20 + 48 \\ 17y = 68 \\ y = 68 \div 17 \\ y = 4 \\ \\ 3x + 2 \times 4 = 5 \\ 3x + 8 = 5 \\ 3x = 5 - 8 \\ 3x = - 3 \\ x = - 3 \div 3 \\ x = - 1[/tex]

Ответ: ( - 1 ; 4 )