4 log x + 5 log x - 7 log x = log 16?

Answer 1

(x^4) * (x^5) / (x^7) = 16

logs are undefined for negative quantities

Answer 2

(X^4) * (X^5) /(X^7) = 16
X^4+5/ X^7 = 16
X^9 ÷ X^7 =16
X^9-7 = 16
X^2= 16
√X^2 = √16
X= 4