The algebraic representation of the sentence’s problem would be:
k - 9
The reason for this is we know that there were k balloons at the beginning of the party. K would represent the initial value or starting point, which is the first number listed.
We also know that by the end of the party, 9 popped. Since 9 balloons out of k balloons popped, we can represent this by subtracting 9 from what we originally had, which was k:
k - 9