Which equation represents a line that passes through (–9, –3) and has a slope of –6?

y – 9 = –6(x – 3)
y + 9 = –6(x + 3)
y – 3 = –6(x – 9)
y + 3 = –6(x + 9)

The answer is:  [D]:  " y + 3 = - 6(x + 9) " .

Explanation:Note:  The equation/formula:


y – y₁ = m(x –x₁) ;

Given:

   slope:  m = -6 ;

point on line: (-9, -3) ;  ↔ (x₁ , y₁) ; ↔ (-9, -3) ; ↔ x₁ = -9 , y₁ = -3 ;

  y – y₁ = m(x –x₁) ;  Substitute our known values; and then, simplify:

       y – (-3) = -6 (x - (-9)) ;

     y + 3 = -6(x + 9) ;  which is:  Answer choice:  [D].