What is a variable expression?
Any group of numbers, symbols (x, y, a, b) and operators (+, - , x) that represent the value of something.
How to write a variable expression:
For this lesson, let us use the following:
Every expression is made up of a combination of the following things:
Terms: Can be a variable, a signed number, a constant multiplied by a variable or variables. In the above example, the terms are 2x, 4y, and 9
Like Terms: Terms that contain the same variable such as 3m, 5m, and 7m.
Constant: A number that cannot change its value. In this example, the constant is 9.
Coefficient: The numerical factor of a multiplication expression that contains a variable. For example in the term 2x, the coefficient of the variable x is 2.
Sample Math Problems
Problem 1: What are the like terms in the expression below?
3x + 5y – 6xy + 19y + 7x
Answer: In this expression, 3x and 7x are like terms and 5y and 19y are like terms
Problem 2. What are the terms in expression below?
3x + 5y + 45 – 6xy + 19y + 7x – 10
Answer: 3x, 5y, 45, -6xy, 19y, 7x, -10
Problem 3: What are the terms in expression below?
3x + 5y + 45 – 6xy + 19y + 7x – 10
Answer: 3x, 5y, 45, -6xy, 19y, 7x, -10
Problem 4: What are the constants in the expression below?
3x + 5y + 45 – 6xy + 19y + 7x – 10
Answer: 45, -10
