Suppose $f (x ) = x^2 + 12$. If $m > 0$ and $f (3m) = 3(f (m))$, what is the value of $m$?
f(x) = x2 + 12
f(m) = m2 + 12
f(3m) = (3m)2 + 12 → 9m2 + 12
f(3m) = 3f(m)
9m2 + 12 = 3(m2 + 12)
9m2 + 12 = 3m2 + 36
6m2 = 24
m2 = 4
m = 2 (or -2)
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