Lg(5x+2)=21lg 6+lg 2

Question

Lg(5x+2)=21lg 6+lg 2

Answer 1

Lg(5x+2)=lg(6^21++2), x=2(6^21-1)/5=2((6^7)^3-1)/5=
=2(6-1)(6^14+6^7+1)/5=2(6^7(6^7+1)+1)=156728888066