Liliana solved the equation below. When she tried to verify her answer, she realized she made an error.

1/3 (x + 18) = 7
1/3x + 6 = 7
1/3x + 6 minus 6 = 7 + 6
1/3x = 1
x = 3

Which correction should Liliana make?

The first step should be One-third x + 54 = 7.
The second step should be One-third x + 6 minus 6 = 7 minus 6.
The third step should be One-third x = 13.
The final step should be x = one-third.