Question

3у^2-7у-10больше0, помните скорей

Answer 1

$3y^2-7y-10\ \textgreater \ 0,\\\\3y^2-7y-10=0,\\D=7^2-4\bullet3\bullet(-10)=49+120=169,\\x_{1,2}=\frac{7\pm\sqrt{169}}{2\bullet3}=\frac{7\pm13}{6},\\x_1=\frac{7+13}{6}=\frac{20}{6}=\frac{10}{3}=3\frac{1}{3},\\x_2=\frac{7-13}{6}=\frac{-6}{6}=-1.\\\\a=3\ \textgreater \ 0 \to x\ \textless \ -1,\ x\ \textgreater \ 3\frac{1}{3}.\\\\OTBET:\ x\ \textless \ -1,\ x\ \textgreater \ 3\frac{1}{3}.$