(1-log(7)28)(1-log(4)28)=? 18log(5) из 9 корней из 5=? log(4 корней из 6)6=?

1)...=(1-log(7)7-log(7)4)(1-log(4)4-log(4)7)=(1-1-log(7)4)(1-1-log(47)=
=-log(7)4*(-log(4)7)=1
2)...=18log(5)√5+18log(5)9=18*0,5+18log(5)9=9+18log(5)9
3)...=1/[log(6)4√6]=1/[log(6)4+log(6)√6]=1/[log(6)4+0,5]