Question

благаю допоможіть з математикою

Answer 1

1.4. Ответ: x=-1 ; y=3

$\left \{ {{x + 3y = 8} \atop {2y - x = 7}} \right. + \\ 5y = 15 \\ y = 3 \\ \\ x + 3y = 8 \\ x + 3 \times 3 = 8 \\ x + 9 = 8 \\ x = - 1$

1.5. Ответ: x=2 ; y=-1

$\left \{ {{4x - 3y = 11 \: \:| \times 2} \atop {5x + 2y = 8 \: \: \: \:| \times 3}} \right. \\ \\ \left \{ {{8x - 6y = 22} \atop {15x + 6y = 24}} \right. + \\ 23x = 46 \\ x = 2 \\ \\ 4x - 3y = 11 \\ 4 \times 2 - 3y = 11 \\ 8 - 3y = 11 \\ - 3y = 3 \: \: \: \: \: \: \: \: \: \: \: \: \: y = - 1$