1. Linear Equations & Slope
• Slope formula: m = (y2 − y1) / (x2 − x1)
• Slope■intercept form: y = mx + b
• Point■slope form: y − y1 = m(x − x1)
• Horizontal line slope = 0
• Vertical line slope = undefined
• Parallel lines have equal slopes
• Perpendicular lines multiply to −1
, 2. Quadratic Equations
• Standard form: ax² + bx + c = 0
• Quadratic formula: x = (−b ± √(b² − 4ac)) / 2a
• Discriminant: b² − 4ac determines number of solutions
• Vertex form: y = a(x − h)² + k
• Axis of symmetry: x = −b / 2a
• Factoring patterns often used to solve quadratics