(1)
ln36
=ln6²
=2ln6
=2ln(2×3)
=2(ln2+ln3)
=2(a+b)
=2a+2b
(2)
ln12
=ln(3×4)
=ln3+ln4
=ln3+ln2²
=ln3+2ln2
=b+2a
(3)
ln(2^9×3^11)
=ln2^9+ln3^11
=9ln2+11ln3
=9a+11b
(4)
ln216
=ln(36×6)
=ln36+ln6
=ln6²+ln6
=2ln6+ln6
=3ln6
=3[ln(2×3)]
=3(ln2+ln3)
=3(a+b)
=3a+3b