Quiz 2: 2.1-2.3

How can you prove a conjecture is false?

• Counterexample
• Not Possible
• Patterns

Tags

CCSS.HSS.CP.A.3

CCSS.HSS.CP.A.5

Find the next number in the sequence.
1, -1, 2, -2, 3, ___

• 4
• -4
• 3
• -3

Tags

CCSS.3.OA.D.9

• A
• B
• C
• D

Tags

CCSS.5.OA.B.3

Which of the following conjectures is false?

• The product of two even numbers is even.
• The sum of two even numbers is even.
• The product of two odd numbers is odd.
• The sum of two odd numbers is odd.

Tags

CCSS.3.OA.D.9

• A
• B
• C
• D

Tags

CCSS.7.EE.A.2

CCSS.HSA.SSE.A.2

Determine if this conjecture is true. If not, give a counterexample.
The difference of two negative numbers is a negative number.

• true
• false; -11 - (-13)  = 2
• false; -7 - (-5) = 2
• false; -19 - (-17)

Tags

CCSS.7.NS.A.1C

Which is a counterexample of: If a four sided shape has two sides the same length, then it must be a rectangle.

• quadrilateral
• rectangle
• square
• triangle

Tags

CCSS.2.G.A.1

Which is a counterexample of: Any number divisible by 2 is divisible by 4.

• 15÷2
• 20÷4
• 16÷4
• 10÷2

Tags

CCSS.5.OA.B.3

• A
• B
• C
• D

Tags

CCSS.7.SP.C.8B

Which is a counterexample of: If a four sided shape has two sides the same length, then it must be a rectangle.

• quadrilateral
• rectangle
• square
• triangle

Tags

CCSS.2.G.A.1