Answer :
Answer: 1
Step-by-step explanation:
[tex]\displaystyle\\\frac{1}{2}lg\frac{25}{4} -2lg\frac{4}{5} +lg\frac{320}{125}=\\\\lg\sqrt{\frac{5^2}{2^2} } -lg(\frac{4}{5})^2+lg\frac{5*64}{5*25}=\\\\lg\sqrt{(\frac{5}{2})^2 } -lg\frac{4^2}{5^2} +lg\frac{64}{25}=\\\\[/tex]
[tex]lg\frac{5}{2} -lg\frac{16}{25}+lg\frac{64}{25} =\\\\ lg\frac{5}{2}+lg\frac{64}{25} -lg\frac{16}{25} =\\\\lg\frac{5*64}{2*25} -lg\frac{16}{25}=\\\\ lg\frac{5*2*32}{2*5*5}-lg\frac{16}{25}= \\\\lg\frac{32}{5}-lg\frac{16}{25}=\\\\lg\frac{32*25}{5*16}=\\\\lg\frac{16*2*5*5}{5*16} =\\\\lg(2*5)=\\\\lg10 =\\\\1[/tex]