At what value of p is the solution of the equation px-3py + 6 = 0 a pair of numbers (1.5; -1.5).

To find out at what values of the parameter p the equation px – 3py + 6 = 0 is a pair of numbers (1.5; – 1.5), we substitute it into the equation x = 1.5 and y = – 1.5 and solve the resulting linear equation with one variable.

So, we substitute and get

1.5p – 3p * (- 1.5) + 6 = 0;

1.5p + 4.5p + 6 = 0;

We transfer the terms without a variable to the right side of the equation, while changing their sign to the opposite.

1.5p + 4.5p = – 6;

Here are similar ones on the left side of the equation:

6p = – 6;

Divide both sides of the equation by 6:

p = – 6: 6;

p = – 1.

Answer: at p = – 1.