Adrian solved the equation x2+9=16 using the following steps. Review his work carefully, and then follow the instructions.
Line 1: x2+9=16
Line 2: x+3=±4
Line 3: x+3−3=±4−3
Line 4: x=1 and x=−7

Which statement identifies a mistake Adrian made, if any?

In Line 2, he should have subtracted 9 from both sides of the equation because it is not part of the expression that is squared.

In Line 3, he should have added 3 to both sides of the equation to get ±4+3.

He did not make a mistake. His answer is correct.

In Line 4, he subtracted incorrectly. The solutions should be x=±1 and x=±7.