Answer:
(-1, 17)
Step-by-step explanation:
The vertex form of a quadratic equation:
[tex]y=a(x-h)^2+k[/tex]
(h, k) - vertex
[tex]y=x^2+2x+18[/tex]
[tex]y=x^2+2(x)(1)+1^2-1^2+18[/tex] use (a + b)² = a² + 2ab + b² (*)
[tex]y=\underbrace{x^2+2(x)(1)+1^2}_{(*)}-1+18[/tex]
[tex]y=(x+1)^2+17\\\\y=(x-(-1))^2+17[/tex]
h = -1, k = 17
