Here's why:
* Open Sentence: An open sentence is a statement that contains a variable. The truth value of the statement (whether it's true or false) depends on the value assigned to the variable.
* Solution: A solution is a specific value for the variable that makes the open sentence true.
Example:
* Open Sentence: x + 3 = 7
* Solution: x = 4 (because 4 + 3 = 7 is a true statement)