Respuesta :

schvelle
by using completing the Square method ,
-x^2-2x+6
= - ( x^2+2x-6) -> factorise -1
= - ( ( x+1 )^2 - (1)^2 -6 ) -> complete the square
= - ( x+1 )^2 +7
- ( x+1 )^2 =0 -> equip it to 0
-x-1 =0
X = -1
axis of symmetry : x = -1