Answer:
[tex]slope\ of \ line\ b = - \frac{9}{2}[/tex]
Step-by-step explanation:
Since line a and b are parallel, the slope of a = slope of b.
therefore,
[tex]slope\ of \ line\ a = \frac{y_2 - y_1}{x_2-x_1} \ \ \ \ \ x_ 1 = 3 , \ y_ 1 = 6 \ , \ x_2 = 1 , \ y_2 = 15[/tex]
[tex]=\frac{15-6}{1-3}\\\\=\frac{9}{-2}\\\\= - \frac{9}{2}[/tex]
[tex]= slope\ of \ line \ b[/tex]
