The student made an error in Step 1.
The original equation is \( 2x^2 - 10x = 0 \).
When factoring out the greatest common factor (GCF), it should be:
\[ 2x(x - 5) = 0 \]
The student incorrectly factored it as \( 2x(x - 10) = 0 \).
As a result, the correct factored form is not achieved, and thus Step 1 is where the error first occurred.