Solve x2 + 9x + 9 = 0

Question

anonymous · Answer

oh no

anonymous · Answer

we all do

anonymous · Answer

how so?

amistre64 · Answer

i find complete the square to be the most non traumatic way

anonymous · Answer

not if middle term is odd is it?  you can use formula as well

anonymous · Answer

[[x = -9/2+(3/2)*sqrt(5)], [x = -9/2-(3/2)*sqrt(5)]]

anonymous · Answer

although i do like completing the square.  i will let amistre write it that way, i will use the formula 
$$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$ with 
$$a=1,b=9,c=9$$ to get 
$$x=\frac{-9\pm\sqrt{9^2-4\times 9\times 1}}{2}$$or 
$$x=\frac{-9\pm\sqrt{45}}{2}$$
$$x=\frac{-9\pm3\sqrt{5}}{2}$$

amistre64 · Answer

x2 + 9x +9 = 0      ; -9
             -9    -9
---------------

x^2 +9x + ___ = -9+___  ; complete the square; (b/2)^2

(9/2)^2 = 81/4

x^2 +9x + 81/4  = -9(4)/(4)+81/4 ; compact

(x+9/2)^2 = (81-36)/4
                 = 45/4

we need +-sqrt(45/4) so subtract out the 9/2

$$x = -\frac{9}{2}\pm\frac{\sqrt{45}}{2}$$

anonymous · Answer

there two methods all worked out!

anonymous · Answer

awesome!

anonymous · Answer

try this one if ud like If a baseball player hits a baseball from 4 feet off the ground with an initial velocity of 64 feet per second, how long will it take the baseball to hit the ground? Use the equation h = -16t^2 + 64t + 4

amistre64 · Answer

its a fly ball :)

anonymous · Answer

lol

amistre64 · Answer

divide out the common of -4 to get: 4t^2 -16t -1

anonymous · Answer

i got 2+4$$\sqrt{17}$$

amistre64 · Answer

and lets work it :)

4(t^2-4t+4) = 1 + 4(4)

(t-2)^2 = 17

t = 2 +- sqrt(17)/2 if i see it right

amistre64 · Answer

t = 2 + sqrt(17)/2 should do it http://www.wolframalpha.com/input/?i=4t^2+-16t+-1