Jedida's mistake occurred in Step 1. Instead of adding \(4x\) to both sides of the equation, she should have subtracted \(4x\) to move it to the left side.
So, the correct equation after Step 1 should be:
\[ x^2 - 4x - 96 = 0 \]
Since she added \(4x\) instead, her equation was incorrect from that point forward. Therefore, the answer is:
Step 1; she added 4x to both sides instead of subtracting.