9514 1404 393
Answer:
Step 4
Explanation:
In Step 1, the first equation is correctly multiplied by 2.
In Step 2, the two equations from step 1 are correctly added.
In Step 3, the value of x is correctly determined by dividing by 11.
In Step 4, the value of x is incorrectly substituted for y in the original first equation.
The first error is in Step 4.