Intercept form: y=2(x+3)(x-5) standard form? vertex form?

I'm not sure but,

Intercept Form to Standard:

y=2(x+3)(x-5)

y=[x^2-5x+3x-15]

y=[x^2-2x-15]

y=2x^2-4x-30

Standard Form to Vertex:

y=2x^2-4x-30

y=2(x^2-4)-30

y=(x^2-4x+4x)-30-4(-2)

y=2(x-2)^2-22

PS: Im clearly not sure about my answer...

1/4 because there is 4 grades.