Question

How do you write the quadratic `y=-1.8x^2-4.32x+4.896` in vertex form?

Answer 1

`y=-1.8x^2-4.32x+4.896`
can be simplified as
`y = (-1.8)(x^2+2.4x+2.72)`
or
`y = (-1.8)(x^2+2.4x) + 4.896`

The vertex form of a quadratic is
`y = m(x-a)^2+b`
and we have already extracted the `m` value (`-1.8`)

Completing the square
`y= (-1.8)(x^2+2.4x+(1.2)^2) +4.896 +(1.8)(1.2)^2`

`y = (-1.8)(x-(-1.2)) + 7.488`
which is the vertex form with a vertex at `(-1.2 ,7.488)`