Out of the five options, only 6b + 1, 4x + 7, and y - 17 are true expressions because they contain variables and mathematical operations without stating an equality condition. 192 + 8 = 24 is an equation, and y-17 is incomplete.
b + 1: This contains variables (b) and mathematical operations (+), making it an expression.
4x + 7: Similar to the above, this uses variables (x) and operations (+), qualifying as an expression.
y - 17: This also uses a variable (y) and an operation (-), making it an expression.
Not Expressions:
192 + 8 = 24: This is an equation, not an expression, as it states an equality condition between two values.
y-17": While it contains a variable and an operation, the missing closing parenthesis makes it incomplete and not a valid expression.