The video tutorial explains how to write equations using unknowns, focusing on two examples. The first example involves creating an equation for 'nine more than four times a number is 19', emphasizing the commutative property of addition. The second example involves writing an equation for 'the difference between 11 and three times a number is 17', highlighting the importance of order in subtraction.

What is the unknown number in the equation where nine more than four times a number is 19?

• z

• y

• a

• x

Tags

CCSS.6.EE.A.2A

How do you express nine more than four times a number?

• 9x + 4

• 4x + 9

• 4 + 9x

• 9 + 4x

Tags

CCSS.6.EE.A.4

Why are the expressions 4x + 9 and 9 + 4x equivalent?

• Because subtraction is commutative

• Because addition is commutative

• Because division is commutative

• Because multiplication is commutative

Tags

CCSS.6.EE.A.2A

What does the expression 9 + 4x imply?

• Nine times a number more than four

• Four more than nine times a number

• Nine more than four times a number

• Four times a number more than nine

Tags

CCSS.7.EE.B.4A

What is the new problem introduced in the video?

• The quotient of 11 and three times a number is 17

• The product of 11 and three times a number is 17

• The difference between 11 and three times a number is 17

• The sum of 11 and three times a number is 17

Tags

CCSS.6.EE.A.2A

How is the difference between 11 and three times a number expressed?

• 3x - 11

• 11 - 3x

• 11 + 3x

• 3x + 11

Tags

CCSS.6.EE.A.2A

What does the term 'difference' imply in mathematical expressions?

• Division

• Subtraction

• Addition

• Multiplication

Tags

CCSS.7.EE.B.4A

In the equation 11 - 3x = 17, what does 'x' represent?

• An unknown number

• A variable that is always zero

• A known number

• A constant

Tags

CCSS.6.EE.A.2C

What is the result of the expression 11 - 3x?

• x

• 11

• 3

• 17

Tags

CCSS.2.OA.A.1

What mathematical operation is used to find the difference between two numbers?

• Multiplication

• Addition

• Subtraction

• Division

Tags

CCSS.2.OA.A.1