Log(7;X)=log(7;2.5)+4 log(7;2)-log(7;10)

Question

Log(7;X)=log(7;2.5)+4 log(7;2)-log(7;10)

Answer 1

Log₇x=log₇2,5+4*log₇2-log₇10=log₇(2,5*2/10)=log₇0,5
x=0,5.