Please help due today

With this question! what is process of elimination? ? p. s. my brothers acc got banned so add his new one @ yamauchiyamyam17

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Which statements are true? check all that apply. the line x = 0 is perpendicular to the line y = –3. all lines that are parallel to the y-axis are vertical lines. all lines that are perpendicular to the x-axis have a slope of 0. the equation of the line parallel to the x-axis that passes through the point (2, –6) is x = 2. the equation of the line perpendicular to the y-axis that passes through the point (–5, 1) is y = 1.