Помогите решить №785 (2,4)

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;