Answer:
9)
x^2 + 2x + 1 = (x + 1)^2
10)
x^2 - 6x + 9 = (x - 3)^2
Explanation:
To complete the square, add the square of half of the x-term coefficient.
Then use the factoring of a perfect square trinomial.
a^2 + 2ab + b^2 = (a + b)^2
a^2 - 2ab + b^2 = (a - b)^2
9)
x^2 + 2x + 1 = (x + 1)^2
10)
x^2 - 6x + 9 = (x - 3)^2