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anonymous
 5 years ago
solve the quadratic equation by completing square
z^2 +16z + 47 =0
a. z=8+/sqrt17 b. z=8+sqrt17 c. z= 16 +sqrt47 d. z=8 +/ sqrt47
anonymous
 5 years ago
solve the quadratic equation by completing square z^2 +16z + 47 =0 a. z=8+/sqrt17 b. z=8+sqrt17 c. z= 16 +sqrt47 d. z=8 +/ sqrt47

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so z has a coefficient of 1

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so we dont have to worry about it

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i guess you prolly already know that a=1, b=16, and c=47

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0but you get all the z's on one side, and the constants on the other, so you rearrange it so now the equation looks like this: z^2 + 16z = 47

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0now take half of the b coefficient, so (16/2) and square it, so (16/2)^2 so 8^2 = 64

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0add that to both sides of your new equation

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so now you got z^2 + 16z + 64 = 47 + 64

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0now you can simplify that so its z^2 + 16z +64 = 17

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0now FOIL that equation on the left side there...which is simply (z + 8) (z + 8)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0cuz that will make z^2 + 16z + 64 again

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so basically you have (z + 8) ^2 = 17

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so to get rid of the ^2 just take the square root of both sides

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0now u got z + 8 = sq. root 17

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so then it would be 8=. sqrt 17 is that right?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0right...i was just a bit confused by your choice of answers there, but obviously C and D are wrong and since you would subtract 8 to get z by itself then there has to be a 8 in the answer, so yeah A is the right answer...maybe i'm just confusing myself cuz its written on a computer and not on paper lol
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