Question

решите системы уравнений способом подстановки​

Answer 1

$8x - 3y - 7 = 0 \\ 3x + y - 9 = 0 \\ \\ 8x - 3( 9 - 3x) - 7 = 0\\ y = 9 - 3x \\ \\ 8x - 3( 9 - 3x) - 7 = 0 \\ 8x - 27 + 9x - 7 = 0 \\ 17x - 34 = 0 \\ 17x = 34 \\ x = 34 \div 17 \\ x = 2 \\ \\ y = 9 - 3x = 9 - 3 \times 2 = 9 - 6 = 3$

Ответ : (2;3)