Variables
A symbol (usually a letter) that stands for an unknown number.
What is a variable?
An expression for “5 more than a number x.”
What is x + 5?
Solve for x: x + 5 = 12.
What is x = 7?
Write an expression for the total cost of x movie tickets at $10 each.
What is 10x?
Solve for x: x – 4 = 8.
What is x = 12?
The variable in the expression 5x – 3.
What is x?
An expression for “3 times a number y minus 7.”
What is 3y – 7?
Solve for x: 3x = 15.
What is x = 5?
Write an equation for: “Three times a number is 15.”
What is 3x = 15?
Write an expression for “4 times a number minus 7.”
What is 4x – 7?
True or False: A variable can only be a letter.
False (It can be any symbol)
The expression for “a number n divided by 4.”
What is n ÷ 4 or n/4?
Solve for x: 4x – 7 = 9.
What is x = 4?
A pizza costs $12 plus $2 per topping. Write an expression for the cost of a pizza with t toppings.
What is 12 + 2t?
Simplify: 6x – 2x + 5.
What is 4x + 5?
In the equation 2x + 4 = 10, x is called the ____.
What is the variable?
Simplify: 2x + 3x – 4.
What is 5x – 4?
Solve for x: 2(x + 3) = 12.
What is x = 3?
A number minus 7 is equal to 5. Write an equation.
What is x – 7 = 5?
Solve for x: 2(x – 3) = 8.
What is x = 7?
If x = 4, what is the value of 3x + 2?
What is 14?
Write an expression for: “The total cost of x books if each costs $12.”
What is 12x?
Solve for x: 5x – 3 = 2x + 9.
What is x = 4?
If a player scores 5 points for each goal and has 3 bonus points, write an expression for their total points.
What is 5x + 3?
A concert ticket costs $50. Write an expression for the cost of x tickets.
What is 50x?