A rational function is any function which can be defined by a rational fraction, which is an algebraic fraction such that both the numerator and the denominator are polynomials
Http://lbcsd.innersync.com/sites/jhayes/documents/U1M3Gr6pg.49-502015JHayes.pdf
You can do substitution 2x-2=x^2 -x -6; isolate all terms on one side 0= x^2 -x-2x -6+2; combine like terms x^2 -3x -4=0; factor the quadratic (x-4)(x+1)=0; each term is zero x-4=0 so x=4 and x+1=0 so x=-1. Now, y=2•4-2=6 and y=2•(-1) -2= -4 ; solutions for the system are ( 4,6) and ( -1, -4)
Line through P(0, 5) and Q(-1, 8):
slope = m = (y2 - y1) / (x2 - x1) = (8 - 5) / (-1 - 0) = 3 / -1 = -3
line through R(3, 3) and S(5, -1):
slope = m = (y2 - y1) / (x2 - x1) = (-1 - 3) / (5 - 3) = -4 / 2 = -2
Parallel lines have equal slopes. Since the two lines have different slopes, they are not parallel.