Как решить систему уравнения: 3x+8y=13 и 5x-16y=7

Решим систему уравнений методом подстановки:

3x + 8y = 13;

5x - 16y = 7.

3x = 13 - 8y;

5x - 16y = 7.

x = (13 - 8y) / 3;

5x - 16y = 7.

x = (13 - 8y) / 3;

5 * ((13 - 8y) / 3) - 16y = 7.

x = (13 - 8y) / 3;

((13 * 5 / 3) - (8 * 5 * y / 3)) - 16y = 7.

x = (13 - 8y) / 3;

65/3 - 40y/3 - 16y = 7.

x = (13 - 8y) / 3;

- 40y/3 - 16y = 7 - 65/3.

x = (13 - 8y) / 3;

(-40y - 16y * 3) / 3 = (7 * 3 - 65) / 3.

x = (13 - 8y) / 3;

(-40y - 48y) / 3 = (21 - 65) / 3.

x = (13 - 8y) / 3;

-88y/3 = - 44/3.

x = (13 - 8y) / 3;

-88y = - 44.

x = (13 - 8y) / 3;

y = - 44 / - 88.

x = (13 - 8y) / 3;

y = 1/2.

x = (13 - 8 * 1/2) / 3;

y = 1/2.

x = (13 - 4) / 3;

y = 1/2.

x = 3;

y = 1/2.

Ответ: (3; 1/2).