Watch HDToday. EVERYTHING YOU NEED TO KNOW TO ACE PRE-CALCULUS IS AT YOUR FINGERTIPS: functions, polynomials, f(x), RATIONAL FUNCTIONS, standard form for rational functions, disguised rational functions, multiplying rational functions, FOIL (review), dividing rational functions, invert & multiply, compound fractions, adding rational functions, common denominators, subtracting rational functions, all four operations together, graphing rational functions, discontinuities, removable singularity, vertical asymptotes, horizontal asymptotes, finding asymptotes, finding roots, word problems, SYSTEMS OF LINEAR EQUATIONS, solving graphically, algebraic substitution, algebraic elimination, SYSTEMS OF INEQUALITIES, inequality basics, graphing linear inequalities, SYSTEMS OF EQUATIONS WITH MORE THAN TWO VARIABLES