  • Matrices
• Algebra
• Geometry
• Funciones
• Trigonometry
• Coordinate geometry
• Combinatorics
 Suma y resta Producto por escalar Producto Inversa
 Monomials Polynomials Special products Equations Quadratic equations Radical expressions Systems of equations Sequences and series Inner product Exponential equations Matrices Determinants Inverse of a matrix Logarithmic equations Systems of 3 variables equations
 2-D Shapes Areas Pythagorean Theorem Distances
 Graphs Definition of slope Positive or negative slope Determine slope of a line Ecuación de una recta Equation of a line (from graph) Quadratic function Posición relativa de dos rectas Asymptotes Limits Distancias Continuity and discontinuities
 Sine Cosine Tangent Cosecant Secant Cotangent Trigonometric identities Law of cosines Law of sines
 Ecuación de una recta Posición relativa de dos rectas Distancias Angles in space Inner product

Sale prices: find the original price

During a 20% OFF sale, an item is marked $52. What is the regular price? You can find the answer by writing and solving an equation:  original price – 20% of original price = sale price p – 0.20p = 52 0.80p = 52 Simplify 0.80p ÷ 0.80 = 52 ÷ 0.80 Divide both sides by 0.80 p = 65 The original price was$65.

Karyl bought a dress at a 35% discount sale for $32.50. What was the original price of the dress? You can find the answer by writing and solving an equation:  original price – 35% of original price = sale price p – 0.35p = 32.50 0.65p = 32.50 Simplify 0.65p ÷ 0.65 = 32.50 ÷ 0.65 Divide both sides by 0.80 p = 50 The original price of the dress was$50.