At this point Josh apparently overlooked the fact that he needed to take the square root of both sides of the equation. Had he done that, he would have ...
x -3 = ±4
x = 3+4 . . . or . . . 3 -4
x = 7 or -1
_____
Josh reported values of x that would match ...
x -3 = ±16
He <em>violated the equal sign</em> by taking the square root on the left, and multiplying by ±1 on the right. Doing different operations on the two sides of the equation will mean the value of x is changed to something other than what you're looking for.
