Answer:
y = 2x - 3
Explanation:
Calculate the gradient of AB.
m = (y2 - y1) / (x2 - x1)
m = (25 - 15) / (9 - 4)
m = 2
The line parallel to AB will have the same gradient.
Use the equation y - y1 = m * (x - x1) and consider the gradient and point C through which the parallel line passes. This is to find the equation of the line parallel to AB in gradient-intercept form y = mx + c.
y + 15 = 2 * (x + 6)
y + 15 = 2x + 12
y - 2x = 12 - 15
y - 2x = -3
y = 2x - 3