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I can't figure out the answers. For the last one, I think that the answer is D. 19.6ft but I don't know. Sorry. Please show work!

 Sep 12, 2018
 #1
avatar+98091 
+1

-3x^2 + 2x  -  3   =  0

 

a  = -3     b   = 2      c   =  -3

 

 

Using the Quadratic Formula

 

x  = [  - b ±√ [ b^2 - 4ac]  ] /  [ 2a]  =

 

[ -2 ±√ [ 2^2 - 4(-3)(-3) ] ] / [ 2 * -3 ]  =

 

[ -2 ±√ [ 4 - 36] ] / [ -6]  =

 

[ -2 ±√-32 ] / [ -6]  =

 

[-2 ±√ [ (-1)(16)(2) ] ] / -6

 

[-2 ±4i√2 ] / -6  =

 

[ -1 ± 2i√2 ] / -3  =

 

[ 1 ±2i√2 ] / 3   ⇒   "B"

 

 

For the second one the distance  is  √[23^2  - 12^2 ]  = √385  =  19.6 ft   ...correct  !!!

 

 

 

cool cool cool

 Sep 12, 2018
edited by CPhill  Sep 12, 2018
 #2
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+1

Sorry for replying to this so late after you posted. I had to leave the site for a little while. Thank you very much for your help! I appreciate it very much! smiley

Guest Sep 12, 2018

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