How do you convert p(x) = -8x^2 - 64x to vertex form?

I know the answer is p(x) = -8(x + 4)^2 + 128, but I'm unaware of the steps taken to get to that stage.

Any help is appreciated, thanks!

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.

Solve the problem. a student earned grades of c, a, b, and a in four different courses. those courses had these corresponding numbers of credit hours: 4, 5, 1, and 5. the grading system assigns quality points to letter grades as follows: a = 4, b = 3, c = 2, d = 1, and f = 0. compute the grade point average (gpa) and round the result to two decimal places. 3.40 3.50 8.75 2.18

The area of a circle is equal to 1 dm². find the radius of the circle.