Question

Решите систему уравнений способом подстановки​

Answer 1

Ответ:

б)

$2x + 3(5x + 2) - 23 = 0 \\ 2x + 15x + 6 - 23 = 0 \\ 17x - 17 = 0 \\ 17x = 0 + 17 \\ 17x = 17 \\ x = 17 \div 17 \\ x = 1 \\ y = 5 \times 1 + 2 = 5 + 2 = 7$

ответ:х=1;у=7

в)

$3x - 4(3x - 5) - 2 = 0 \\ 3x - 12x + 20 - 2 = 0 \\ - 9x + 18 = 0 \\ - 9x = 0 - 18 \\ - 9x = - 18 \\ x = - 18 \div ( - 9) \\ x = 2 \\ y = 3 \times 2 - 5 = 1$

ответ:х=2;у=1