What is the vertex of the parabola y = x² + 8x + 5 ?

y = x² + 8x + 5

a = 1, b = 8, and c = 5 {in standard form}

-b

---- is the x-coordinate of the vertex

2a

-8

------ = x-coordinate of vertex {substituted 1 for a and 8 for b}

2(1)

x-coordinate of vertex is -4 {simplified}

y = x² + 8x + 5 {the equation of the parabola}

y = (-4)² + 8(-4) + 5 {substituted -4 for x into equation to find y-coordinate of vertex}

y = 16 - 32 + 5 {evaluated exponent and multiplied}

y = -11 {added and subtracted}

**(-4 , -11) is the vertex of the parabola**

*- Algebra House*