First find the y-intercept value by substituing the slope and coordinates of the

given point in the equation.

y = mx + b                (Slope-intercept form line equation)

1 = 3 + b                  (Substitute 3 for m, 1 for x, and 1 for y)

1 – 3 = 3 + b – 3     (Subtract 3 from each side)

1 – 3 = 3 – 3 + b     (Commutative property: a + b = b + a)

1 – 3 = b                  (Additive inverse property: 3 – 3 = 0)

b = – 2                     (Subtract: 1 – 3 = –2)

Now substitute m = 3 and b = – 2 slope-intercept form line equation.

y = 3x + (– 2)   

y = 3x – 2                (Simplify)

The equation of the line that passes through the point (1, 1) and has a slope of 3 is

y = 3x – 2.