Set the formula to direct proportionality if its graph passes through the point M (3; -2).

Direct proportionality is a function of the form y = kx, the graph of which is a straight line passing through the origin point O (0; 0).

To set direct proportionality by the formula, the graph of which passes through the point M (3; -2), means to calculate the value of its slope k and substitute it in the general form of the function y = kx. To do this, substitute the coordinates of the point M (3; -2) into the formula y = kx instead of x and y and solve the resulting equation:

-2 = 3k.

Here k is an unknown factor equal to the quotient of the product -2 and the known factor 3:

k = -2/3.

Answer: y = (-2/3) x.