=1+sin(π/6)=1+(1/2)=1+0,5=1,5;
2) lg(50a)-lg(5b)=lg((50a)/(5b))=lg(10*(a/b))=lg10+lg(a/b)=
=1+cos(π/3)=1+(1/2)=1+0,5=1,5;
3) log_(6) (9a)+log_(6) (4b)=log_(6) (9a*4b)=log_(6) (36*ab)=
=log_(6) 36+log_(6) (ab)=1+tg(π/1)=1+1=2;
4) log_(3) (6a)-log_(3) (54b)=log_(3) ((6a)/(54b))=log_(3) ((1/9)*(a/b))=
=log_(3) (1/9)+log_(3) (a/b)=-2+ctg(π/2)=-2+0=-2.