Does this able represent a function? Why or why not?

What will the graph look like for a system of equations that has no solution? a. the lines will be perpendicular. b. the lines will cross at one point. c. both equations will form the same line. d. the lines will be parallel.

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x

X+y=-4 x-y=2 use elimination with adding and subtraction