[tex]\displaystyle\bf\\\left \{ {{7x - 5y = 29 \: \: | \times ( - 1)} \atop {7x + 8y = - 10 }} \right. \\ \displaystyle\bf\\ + \left \{ {{ -7 x + 5y = - 29} \atop {7x + 8y = - 10 }} \right. \\ \\ 5y + 8y = - 29 - 10 \\ 13y = - 39 \\ y = - 39 \div 13 \\ y = - 3 \\ \\ 7x - 5 \times ( - 3) = 29 \\ 7x + 15 = 29 \\ 7x = 29 - 15 \\ 7x = 14 \\ x = 14 \div 7 \\x = 2[/tex]

Ответ: ( 2 ; - 3 )