a)
[tex]\text{L}=5^{25}\cdot25^5=5^{25}\cdot(5^2)^5=5^{25}\cdot5^{2\cdot5}=5^{25}\cdot5^{10}=5^{25+10}=5^{35}\\\\\text{P}=5^{35}\\\\\text{L}=\text{P}[/tex]
b)
[tex]\text{L}=4^{20}\cdot8^{40}=(2^2)^{20}\cdot(2^3)^{40}=2^{40}\cdot2^{120}=2^{160}=(2^4)^{40}=16^{40}\\\\\text{P}=16^{40}\\\\\text{L}=\text{P}[/tex]
c)
[tex]\text{L}=27^9\cdot9^{27}=(3^3)^9\cdot(3^2)^{27}=3^{27}\cdot3^{54}=3^{81}=(3^3)^{27}=27^{27}\\\\\text{P}=27^{27}\\\\\text{L}=\text{P}[/tex]