Linear proportionality graph passes through points A (-8; -72) and B (x; 45). Find the value of x.

Let the sought direct proportionality be given using the relation y = k * x, where k is some real number.

If the graph of this direct proportionality passes through point A (-8; -72), then the following relationship should be met:

-72 = k * (-8).

Solving this equation, we get:

k = -72 / (-8);

k = 9.

Therefore, this direct proportionality is given by the equation y = 9x.

If the graph of this direct proportionality passes through the point B (x; 45), then the following relationship should be met:

45 = 9 * x.

Solving this equation, we get:

x = 45/9;

x = 5.

Answer: x = 5.