1) log_3(x^2+2x)<1<br> 2) x^2+x-20 (1,5)* x. =<1<br> 3)sin^2a+cos^2a+tg^2B 4)(1/3)^x^2-4x-1>9^x-1
Log_3(x^2+2x)=3^0 x^2+2x=0 X(x+2)=0 X=0. X=-2.