Question

Solve x2 + 9x + 9 = 0

Answer 1

oh no

Answer 2

we all do

Answer 3

how so?

Answer 4

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

Answer 5

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

Answer 6

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

Answer 7

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
\[x=\frac{-9\pm\sqrt{45}}{2}\]
\[x=\frac{-9\pm3\sqrt{5}}{2}\]

Answer 8

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

\[x = -\frac{9}{2}\pm\frac{\sqrt{45}}{2}\]

Answer 9

there two methods all worked out!

Answer 10

awesome!

Answer 11

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

Answer 12

its a fly ball :)

Answer 13

lol

Answer 14

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

Answer 15

i got 2+4\[\sqrt{17}\]

Answer 16

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

Answer 17

t = 2 + sqrt(17)/2 should do it

http://www.wolframalpha.com/input/?i=4t^2+-16t+-1