Find vertex and min/max
y=-2(x+9)(x+3)

max at (- 6, 18 )

Step-by-step explanation:

Given the equation of a parabola in intercept form

y = a(x + c)(x + d)

• If a > 0 then min vertex

• If a < 0 then max vertex

y = - 2(x + 9)(x + 3) ← is in intercept form

with a = - 2 < 0 then max vertex

y = - 2(x + 9)(x + 3) ← expand factors using FOIL

  = - 2(x² + 12x + 27) ← distribute parenthesis by - 2

y = - 2x² - 24x - 54 ← in standard form

with a = - 2 and b = - 24

The x- coordinate of the vertex is

x = - = - = - 6

Substitute x = - 6 into the equation and evaluate for y

y = - 2(- 6 + 9)(- 6 + 3) = - 2(3)(- 3) = 18

vertex = (- 6, 18 ) and is a max

answer: 7

step-by-step explanation: