1) log5(1/7) - log√5(25/√7)
= log5(1/7) - log5(25√5/√7)
= log5(1/7 * √7/5)
= log5(√7/35)

2) 8^(log4(3) - 1)
= 8^log4(3) / 8^1
= 8^log4(3) / 8
= (4^2)^log4(3) / 8
= 4^(2log4(3)) / 8
= 4^[log4(3^2)] / 8
= 4^log4(9) / 8
= 9 / 8
= 1.125