SOLUTION: how do you solve the equation by completing the square. z2+5z-6=0 (z is squared)

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Question 812968: how do you solve the equation by completing the square. z2+5z-6=0 (z is squared)
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

how do you solve the equation by completing the square. 

z^2+5z-6=0  

First add and subtract %285%2F2%29%5E2

z^2+5z + 25/4 -25/4 -6 = 0 

%28z+%2B+5%2F2%29%5E2+-+49%2F4+=+0

%28z+%2B+5%2F2%29%5E2+=+49%2F4+

    z + 5/2 = ± 7/2

    z =  -5/2 ± 7/2

 z = -6, 1