Rules for Numbers Flashcards
1
Q
Law of associativity for addition
A
(x + y) + z = x + (y + z)
2
Q
Law of commutativity for additon
A
x+y = y +x
3
Q
Law of identity for addition
A
x+0= x
4
Q
law of inverses for addition
A
-x + x = 0
5
Q
Law of associativity for multiplication.
A
(xy)z = x(yz)
6
Q
law of commutativity for multiplication
A
xy = yx
7
Q
law of identity for multiplication
A
x1 = x
8
Q
law of inverses for multiplication
A
X ≠ = then 1/xX = 1
9
Q
the distributive law
A
x(y + z) = xy + xz
10
Q
if x > 0 and y > 0
x + y is?
A
x + y > 0
11
Q
if x > 0 and y > 0
then xy is ?
A
xy > 0
12
Q
[a, b]
A
a ≤ x ≤ b
13
Q
(a, b)
A
a < x < b
14
Q
[a, b)
A
a ≤ x < b
15
Q
(a, b]
A
a < x ≤ b
16
Q
[a, ∞)
A
a ≤ x
17
Q
(- ∞, b]
A
x ≤ b
18
Q
(a, ∞)
A
a < x
19
Q
(-∞, b)
A
x < b
