What is the negative reciprocal?

-23/17

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.

For the equations below which statement is true ?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)