Question

How to solve for x?
5 = log_3 (x^2 + 18)

Answer 1

\[5 = \log_3 (x^2 + 18) \]
let x^2 + 18=a
so
\[5 = log_3 a \]
Does this help?

Answer 2

Not really , my knowledge with logarithms is little... Dumb in this area, you could say.

Answer 3

log_a x = N
A^n = x
so..
log_3 a = 5
3^5 = a
?

Answer 4

\[\log_3(a) = 5\]\[Log_ab=c~~~~~~~->~~~~~~a^c=b~~~~~so,~~~~YES,~~you~~got~~it!\]

Answer 5

Awesome! and the rest is algebra.
243 = x^2 + 18
x^2 - 225
(x+15)(x-15)
x = 15, -15,

Answer 6

243 = x^2 + 18
243 -18= x^2
and the answer is there CORRECT!
225=x^2
x=± 15

Answer 7

thanks.

Answer 8

Anytime!