²log3 =x dan ²log5 =y , maka ⁴log 45 adalah.

4log 45
=2^log (9×5)
=2^log (3^x5)
=2^log3^+2^log5
=2log3+1/2 2log 5
=x+1/2y

2^2 ^log 3^2 x 5
2/2 2^log 3 x 5
2log3 + 2 log 5
X+ y