The graph of the functions y = kx + b intersects the ordinate at point A (0; 4) and passes through point

The graph of the functions y = kx + b intersects the ordinate at point A (0; 4) and passes through point B (-2; 8). find the value of k and b.

Substituting the coordinates of the given points into the equation of the straight line, we obtain the system of equations:

k * 0 + b = 4;

k * (-2) + b = 8.

From the first equation we get:

b = 4.

Let’s substitute in the second:

-2k + 4 = 8;

-2k = 4;

k = -2.

Answer: the equation of the straight line looks like this y = -2x + 4.