Tyler made an error in the third step of his work:
Original Third Step:
\[ 9 + (-20x) + (-6) \]
He incorrectly combined the constants 9 and -6 as 3. The correct combination is \(9 - 6 = 3\). Therefore, the corrected third step should be:
Corrected Third Step:
\[ 3 + (-20x) \]
So, the corrected expression after using the distributive property is \(3 - 20x\), which aligns with Mai's expectation.