Question

методом додавання пж быстрее

Answer 1

$\displaystyle\bf\\\left \{ {{3x + y = 4 \: \: | \times 2} \atop {5x - 2y = 14 }} \right.\\ \displaystyle\bf\\ + \left \{ {{6x + 2y = 8} \atop {5x - 2y = 14 }} \right. \\ \\ 5x + 6x = 8 + 14 \\ 11x = 22 \\ x = 22 \div 11 \\ x = 2 \\ \\ 3 \times 2 + y = 4 \\ 6 + y = 4 \\ y = 4- 6 \\ y = - 2$

Ответ: ( 2 ; - 2 )