Answer:
[tex]\frac{-5}{9}[/tex]
Step-by-step explanation:
The slope of two parallel lines is the same. As long as the y-intercept is different then, the lines are parallel. Therefore, if the slope of line b is [tex]\frac{-5}{9}[/tex] then the slope of line c must also be [tex]\frac{-5}{9}[/tex].
