SOLUTION: solve (logx)^2+4logx-9=0

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Question 870274: solve (logx)^2+4logx-9=0
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
%28log%28%28x%29%29%29%5E2%2B4%2Alog%28%28x%29%29-9=0
u=log%28%28x%29%29
u%5E2%2B4u-9=0
Complete the square,
%28u%5E2%2B4u%2B4%29-9=4
%28u%2B2%29%5E2=13
u%2B2+=+0+%2B-+sqrt%2813%29
u=-2+%2B-+sqrt%2813%29
log%28%28x%29%29=-2+%2B-+sqrt%2813%29
x=10%5E%28-2%2B-sqrt%2813%29%29