№ 12: (1) log₃ 18 + log₃ 12 − log₃ 8; (2) log₇ ³√49; (3) 5^(1 + log₅ 2); (4) log₃₂ 1; (5) log₁₄ 14.

1) log₃(18 × 12 ÷ 8) = log₃ 27 = 3.

2) ³√49 = 7^(2/3), поэтому log₇ ³√49 = 2/3.

3) 5^(1 + log₅ 2) = 5 × 2 = 10.

4) log₃₂ 1 = 0.

5) log₁₄ 14 = 1.