Step-by-step explanation:
the general equation of a line is
y = ax + b
a is the slope of the line.
b is the y-intercept (the point, where the line crosses the y-axis, meaning the y value when x=0).
we get b by using the point coordinates in the equation and solve for b :
6 = -3×4 + b = -12 + b
18 = b
so, the full line equation is
y = -3x + 18
which is answer C : 3x + y = 18