Respuesta :

Answer:

a line with a gradient of

[tex] \frac{ - x}{3} [/tex]

Step-by-step explanation:

parallel lines have equal gradients, i.e the value of m, has to be the same.

therefore:

[tex]x + 3y = - 21 \\ 3y = - x - 21 \\ y = \frac{ - x}{3} - 7[/tex]