your friend thinks that k - 3.5 = 21 is a statement is your friend correct

yes, if he thinks it's an open statement.

To determine if your friend is correct, we need to solve the equation:

k - 3.5 = 21

To isolate the variable "k" on one side of the equation, we can add 3.5 to both sides:

k - 3.5 + 3.5 = 21 + 3.5

This simplifies to:

k = 24.5

So, the correct solution to the equation is k = 24.5.

Therefore, if your friend believes that k - 3.5 = 21 is a statement, they are incorrect. The correct equation is k - 3.5 = 24.5.