Slope-intercept form: y = mx + b
(m is the slope, b is the y-intercept or the y value when x = 0 --> (0, y) or the point where the line crosses through the y-axis)
You know:
m = 3
b = -4 So substitute/plug it into the equation
y = mx + b
y = 3x + (-4)
y = 3x - 4 Your answer is a
