Question

Which equation represents a line that passes through the point ( 6 , − 3 ) and is parallel to the graph of y = 3 x + 1 ?

Answer 1

Answer:

              y + 3= 3(x - 6)        ←    point-slope form

             y = 3x - 21           ←    slope-intercept form

             3x - y = 21         ←    standard form

Step-by-step explanation:

The point-slope form of the equation of line it's y - y₁ = m(x - x₁), where m is the slope and (x₁, y₁) is the point the line passing through.

y=m₁x+b₁   ║   y=m₂x+b₂   ⇔    m₁ = m₂

{Two lines are parallel if  their slopes are equal}

y = 3x + 1   ⇒    m₁ = 3    ⇒    m₂ = 3

(6, -3)    ⇒    x₁ = 6,  y₁ = -3

point-slope form:

y - (-3) = 3(x - 6)

y + 3 = 3(x - 6)

y + 3 = 3x - 18              {subtact 3 from both sides}

y = 3x - 21        ←    slope-intercept form

-3x + y = -21                 {multiply both sides by (-1)}

3x - y = 21         ←    standard form