about this site / | B S R basic skills review / | C N S geometric construction / | D T A data analysis and statistics / | E X P exponents and roots / F N C functions / G E O foundations of geometry / L N R linear equations / P A V perimeter, area, and volume / P L Y polynomials / P R B probability / P T H the pythagorean theorem / Q D R quadratic equations / R D X radical expressions / R P S ratio, proportion, and similarity R T N rational numbers / R T X rational expressions / S V E single-variable equations / S V I single-variable inequalities / S Y S systems of equations / |