1) log3 x=4 log3 a+ 7log3 b; log3x = log3 a^4+log3 b^7; log3 x = log3 a^4*b^7;
x= a^4*b^7;
2) log5 x= 2log5 a -3log5 b; log5 x = log5 a^2 - log 5 b^3; log5 x = log5 (a^2/b^3);
x = a^2/b^3;
3) log 1/2 x = 2/3log1/2 a - 1/5log1/2 b;
log1/2 x = log 1/2 a^2/3 - log1/2 b^1/5;
log1/2 x = log 1/2 (a^2/3)/(b^1/5);
x= (a^2/3)/(b^1/5);
4) log2/3 x = 1/4log2/3 a + 4/7log 2/3 b;
log2/3 x = log2/3 (a^1/4)+ log2/3 (b^4/7);
log 2/3 x = log 2/3 (a^1/4*b^4/7);
x= a^1/4*b^4/7;