Question

Can someone please help i need to write the equation of the green line

Answer 1

f(x) = ax + b

(0, -4):

           f(0) = a•0 + b

           f(0) = b      ⇒     b = -4

(12, 0):

           0 = a•12 + b

           0 = 12a - 4

           4 = 12a

           $a=\frac4{12}=\frac13$

The equation of the green line:

                                                   $\underline{\,y=\frac13x-4\,}$

or:      $y=\frac13x-4$

         $-\frac13x+y+4=0\\\\\underline{x-3y-12=0}$