Question

How do you solve `x^2 - 2x + 1 = 4` by completing the square?

Answer 1

Answer is x=3, -1

The square is already complete on the left side and it is `(x-1)^2`. Therefore problem is now to solve for x the equation `(x-1)^2`=4. Take square root on both sides to get x-1=`+-`2. This gives x=3, -1.