Example 1easy
- A)A) A constant can change its value.
- B)B) A variable has a fixed numerical value.
- C)C) In the expression 5x + 7, 'x' is a variable and '7' is a constant.
- D)D) Only letters of the alphabet can be variables.
Step-by-step solution
- Variables are symbols (usually letters) that represent unknown values that can change. Constants are numbers that have fixed numerical values.
- Option A is false because constants have fixed values. Option B is false because variables represent values that can change.
- Option D is false as symbols other than letters can sometimes represent variables, though letters are most common. Option C correctly identifies 'x' as a variable (unknown value) and '7' as a constant (fixed value).
Answer: C) In the expression 5x + 7, 'x' is a variable and '7' is a constant.