9x2+25<30x 3x2+x<0 2x(x-1)<3(x+1)

$9x^2+25\ \textless \ 30x\\9x^2-30x+25\ \textless \ 0\\9x^2-30x+25=0\\(3x-5)^2=0\\(3x-5)^2\ \textless \ 0$
x∈∅
$3x^2+x\ \textless \ 0\\x(3x+1)\ \textless \ 0\\x(3x+1)=0\\x=0\\x=-\frac{1}{3}$
x∈(-1/3;0)
$2x(x-1)\ \textless \ 3(x+1)\\2x^2-2x\ \textless \ 3x+3\\2x^2-5x-3\ \textless \ 0\\2x^2-5x-3=0\\D=25+24=49=7^2\\x=\frac{5+7}{4} =3\\x=-\frac{1}{2}$
x∈(=1/2;3)