SOLUTION: solve for x log2x + log2(x^2-9) = log2(-5x)

Question 141096: solve for x
log2x + log2(x^2-9) = log2(-5x)
Answer by scott8148(6628) (Show Source): You can put this solution on YOUR website!
adding logs is multiplying quantities

taking antilog __ x(x^2-9)=-5x __ x^3-9x=-5x __ x^3-4x=0 __ x(x^2-4)=0 __ x(x+2)(x-2)=0

x=0

x+2=0 __ x=-2

x-2=0 __ x=2

logarthms are NOT defined for quantities <=0
__ the algebra generates the "solutions" __ but the logs aren't realistic
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