8th grade pre-algebra: Words and Expressions, Variables and Expr

What is the value of x in the equation 2x + 9 = 21?

• 6
• 11
• 15
• 7

What is the value of 4x + 7y when x = 3 and y = 2?

• 29
• 15
• 35
• 29

Which of the following expressions represents 'twice a number decreased by three'?

• 2x - 3
• 2x + 3
• 3x - 2
• 2x - 3

What is the value of 5(x - 2) when x = 7?

• 15
• 35
• 21
• 15

What is the value of y in the equation 5y - 8 = 17?

• 5
• 12
• 3
• 5

Which of the following is an algebraic expression?

• 9x + 3
• 9 + 3
• 12 - 4
• 5 + 2

Evaluate the expression for y = 2: 3y^2 - 4y + 1

• 9
• 5
• 12
• 4

Which property states that the product of any number and 0 is always 0?

• Zero property
• Zero property
• Associative property
• Distributive property

Which of the following is a numerical expression?

• 7 + 3
• 4y + 2
• 2x^2 - 5x
• 7x - 3

What is the difference between a variable and a constant?

• A variable is a symbol used to represent an unknown value or quantity, while a constant is a value that does not change.
• A variable and a constant are the same thing.
• A variable is a value that does not change, while a constant represents an unknown value.
• A variable is a value that changes, while a constant is a known value.