0.6y : 9 = 1.3-y : 4.5

Найдем корень уравнения.

(0.6 * y) / 9 = (1.3 - y) / 4.5;

Упростим уравнение.

(6/10 * y) / 9 = (1.3 - y) / (9/2);

(3/5 * y) / 9 = (1.3 - y) / (9/2);

3 * y/5 * 1/9 = (1.3 - y) / 1 * 2/9;

3 * y/5 = (1.3 - y) * 2;

3 * y = 5 * 2 * (1.3 - y);

Раскроем скобки.

3 * y = 10 * (1.3 - y);

3 * y = 10 * 1.3 - 10 * y;

3 * y = 13 - 10 * y;

3 * y + 10 * y = 13;

y * (3 + 10) = 13;

y * 13 = 13;

13 * y = 13;

y = 13/13;

y = 1.