Page 112 - Mathematics GRADE 9, DE-STREAMED (MTH1W)

expression could you use to determine the number of greetings for any number of people in the room?
C1.3 Algebraic Expressions and Equations
compare algebraic expressions using concrete, numerical, graphical, and algebraic methods to identify those that are equivalent, and justify their choices
Teacher supports
Examples
• algebraic expressions:
o non-simplified polynomials with a single variable involving addition or subtraction; for
example, compare 3x + 5x with −x + 6x
o simplified polynomials with a single variable and non-simplified polynomials involving
multiplication; for example, compare 2m + 10 with 2(m + 5)
o polynomial expressions involving multiple operations; for example, compare −2x(x + 5) − 2
with −2(x2 + 5x − 1)
o algebraic expressions involving integer exponents; for example, compare (a6)(a3) with
a2
(a3)4(a−5)
• comparing using concrete methods:
o represent and compare algebraic expressions using concrete tools such as algebra tiles,
colour tiles, and pattern blocks:
▪ compare 3(x + 2) and 3x + 6 using algebra tiles:
3(x + 2)
3x + 6
These expressions are equivalent because they are represented by the same number of each tile.
• comparing using numerical methods:
o use substitution to test the output for various inputs:
▪ compare 2(x – 3) + 3x and 5(x – 2) + 2 using substitution: 111