A02 E question 15

(3x)^lg3=(4x)^lg4

(3^lg3)(x^lg3)=(4^lg4)(x^lg4)

(3^lg3)/(4^lg4)=(x^lg4)/(x^lg3)
                       =x^(lg4-lg3)

[(3^lg3)/4^lg4)]^(1/lg4-lg3)=x

x=1/12