Line MN passes through points M(4, 3) and N(7, 12). If the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b?
Slope = -9/-3 = 3
y = 3x + b sub in one of the given points to calc b
3 = 3(4) + b b = -9
Or use point slope
we know slope is 3
so
y−3=3(x−4)y−3=3x−12y=3x−9
so -9