Grade 9 Math Key Words

Solving Equations Lowest Common Denominator term numerator denominator distributive property expand  monomial, binomial, polynomial BEDMAS like terms, unlike terms integers coefficients variables inverse operations isolate variable substitute variable  reciprocal cross-multiplying constant mixed/improper fractions gathering like terms

Things to remember: BEDMAS simplify before multiplying fractions reduce answer if possible check negatives

Linear Relations quadrant (1,2,3,4) origin x and y axis independent/dependent ordered pairs rate of change/slope undefined negative/positive table of values partial/direct variation linear relationship interpolation/extrapolation line segment vertical/horizontal y or x intercept rise/run perpendicular/parallel break-even point profit, revenue, cost type 1, 2, 3 lines

Things to remember: label the axis appropriate scale arrows on line profit=revenue-cost break-even point is when cost=revenue let statement for word problems "x" must not be in denominator must be able to explain slope in context check for integer errors

Modelling Linear Relationships  point of intersection standard form slope-y-intercept form y in terms of x (y=?) variables break-even point

Things to remember: no arrows on graphs let statement therefore statement use slope in table of values when finding intercepts, 'sub' into original equation simplify money should be expressed as decimal use key words in answers (e.g. interpolate)

Algebra/Exponents term variable term constant term variable coefficient like/unlike terms polynomials exponent base power

Things to remember: lowest terms once you multiply, there should be no brackets use empty brackets when substituting try to keep 'x's and 'y's together let statement

Geometry angles polygons quadrilateral supplementary opposite angles'co-interior angles rhombus mid-segments/midpoints parallel bisect complimentary isosceles alternate transversal parallel lines corresponding exterior/remote angles parallelogram kite diagonals perpendicular adjacent

Things to remember: let and therefore statement exact values characteristics of shapes

Investigating Relationships trend outliers line of best fit correlation mean fit line convenience sampling random sample stratified sample cluster sampling finite difference linear relationship non-linear relationship

Things to remember: use points of line of best fit to find slope use different symbol on graph for mean point outliers can be significantly below/above if Y differences are positive, slope is increasing and vice versa in stories about graphs include times, slopes, etc.

Key Words