What Is A Variable?
A variable is a symbol, usually a letter (like x, y, or a), that represents a number we do not know yet, or a value that can change.
Think of a variable as an empty box. You can put any number inside the box, and the variable stands for whatever number is currently in it.
Example: In the statement, "A number plus five equals ten," we can use the variable x to represent the unknown number:
x + 5 = 10
Here, x is the variable.
(By the way, x would equal to 5 in this situation.)
What Is A Expression?
An expression is a mathematical phrase that can contain numbers, variables, and operation signs (like +, -,*, /). An expression does not contain an equals sign (=).
Parts Of An Expression
Expressions have specific parts that are important to identify:
Term: A single number, a single variable, or a product/quotient of numbers and variables. Terms are separated by addition or subtraction signs.
Coefficient: The numerical factor multiplied by a variable in a term.
Constant: A term that is just a number; its value does not change.
Challenge - Try and figure out the parts of this expression: 4x + 7 - y - Answer Below
Answer:
Terms: The terms are 4x, 7, and -y.
Coefficient: In the term 4x, the number 4 is the coefficient. In the term -y (which is -1y), the coefficient is -1.
Constant: The number 7 is the constant.