Transcript Algebra 1

Algebra 1
Chapter 1-2
The Commutative and Identity
Properties
Group Work

True or False
1.
2.
3.
4.
3+8=8+3
6–3=3–6
10 / 5 = 5 / 10
4•6=6•4
Vocabulary
Commutative Properties – we can change
the order when adding or multiplying
without changing the sum or product.
 Equivalent Expressions – expressions such
as x + 2 and 2 + x, which always result in
the same number when we substitute any
value for their variables.

Example…(Commutative Property)

Write an expression equivalent to each
using a commutative property:
y+5
 xy
 5 + ab

Try This…

Use a commutative property to write an
equivalent expression.
1.
2.
3.
x+9
pq
xy + t
Vocabulary…
Additive Identity – adding 0 to any number
gives that number.
 Multiplicative Identity – multiplying 1 to
any number gives that number
 (Dividing a number by itself gives 1)

These all have the value of 1
n/n
m+3/m+3
 5y + 4 / 5y + 4

Examples…

Write an equivalent expression for 2 / 3 by
multiplying by 1.
Try This…

Write an equivalent expression for 7 / 5 by
multiplying by 1.

Write an equivalent expression for 3 / 8 by
multiplying by 1.
Examples…

Write an expression equivalent to x / 2 by
multiplying by 1. Use y / y for 1.
Try This…

Write an expression equivalent to y / 2x by
multiplying by 1. Use z / z for 1.

Write an expression equivalent to 2m / n by
multiplying by 1. Use p / p for 1.
Vocabulary…
Factor – numbers that you multiply to find
the product.
 Simplest Form – when the only common
factor of the numerator and the denominator
is 1.
 Simplifying – The process of finding the
simplest form.

Examples…
(Simplifying Expressions)

Simplify:

10 / 15

36 / 24
Try This…

18 / 27

48 / 18

56 / 49
More Simplifying Examples…

18 / 72
72 / 9
 Try This

27 / 54
 48 / 12

And Even More…

xy / 3y

x / 5xy

4cd / 2c
Try This…

5xy / 3x

m / 8 mn

14ab / 7b