Make the equation of the straight line passing through the points: 1) A (9; -3) B (-2; 0) 2) A (3; -1) B (-7; -3).

In order to draw up an equation of a straight line passing through points with coordinates A (9; -3) and B (-2; 0), we will compose and solve a system of equations.

General equation of the straight line y = kx + b;

Let’s compose the system by substituting the point coordinates instead of x and y in the equation.

System of equations:

-3 = 9k + b;

0 = -2k + b.

We solve the resulting system using the substitution method:

9k + b = -3;

b = 2k;

Substitute in the first equation instead of b the expression from the second.

9k + 2k = -3;

b = 2k;

We solve the first equation:

11k = -3;

k = -3/11;

b = 2 * (-3/11) = -6/11.

We get the equation:

y = -3 / 11x – 6/11.