The graph of the function y = kх + m passes through point A (2; 5) and crosses the OY
The graph of the function y = kх + m passes through point A (2; 5) and crosses the OY axis at point (0; -3). Find the value of the coefficients k and m.
If the straight line y = kx + m passes through the point O (x1; y1), then the following relation is true:
y1 = k * x1 + m.
According to the condition of the problem, the straight line y = kx + m passes through the point A (2; 5), therefore, the following relation is true:
5 = k * 2 + m.
It is also known that this line passes through the point B (0; -3), therefore, the following relation is true:
-3 = k * 0 + m.
We solve the resulting system of equations.
From the second equation follows:
m = -3.
Substituting the found value m = -3 into the equation 5 = k * 2 + m, we get:
5 = k * 2 – 2;
k * 2 = 5 + 2;
k * 2 = 7;
k = 7/2;
k = 3.5.
Answer: m = -3; k = 3.5.