Answer:
(x+2)^2=19
Step-by-step explanation:
What you do is you need to make it into a perfect square. So what you do is you need to divide the 4 by 2 then square the answer to get 4.
You then add it to the end of the equation and to 15 to get x^2+4x+4=19.
Then you make the square to get (x+2)^2=19.
