Question

Write f(x)= a(x-h)2+k and identify the vertex

Answer 1

Hello : 
2x²+4x-5 = a(x-h)2+k =a(x²-2xh+h²)+k
2x²+4x-5 = ax²-2ahx +ah² +k
a=2.....(1)
-2ah = 4.....(2)
ah²+k=-5...(3)
in (2) : -4h=4      h=-1
in(3) : 2(-1)²+k=-5    k = -7
conclusion : 2x²+4x-5 = 2(x+1)²-7
the vertex is : A(-1,-7)