Completing the square for vertex form | Quadratic equations | Algebra I | Khan Academy

Which of the following represents the standard form of a quadratic equation?

• y = A(x - h)^2 + k

• y = ax^2 + bx + c

• y = mx + b

• y = a(x - p)(x - q)

What is the initial step to rewrite the quadratic equation y = -3x^2 + 24x - 27 in vertex form?

• Add 27 to both sides of the equation.

• Divide the entire equation by -3.

• Factor out -3 from the terms containing x.

• Square the coefficient of the x term.

When completing the square for the expression x^2 - 8x, what constant term should be added to make it a perfect square trinomial?

• -4

• 8

• 16

• 64

What are the coordinates of the vertex for the quadratic equation y = -3(x - 4)^2 + 21?

• (-4, 21)

• (4, -21)

• (4, 21)

• (-4, -21)