Question

Solve:
$\begin{array}{c}1)3x^2=-11x-10\\ 2)25x(x+1)=-4\end{array}$

Answer 1

1) $3x^2=-11x-10$

$3x^2+11x+10=0$

$\frac{-b\pm \sqrt{b^2-4ac}}{2a}=-\frac{-11\pm \sqrt{121-4\left(3\right)\left(10\right)}}{2\left(3\right)}$

$=\frac{-11\pm 1}{6}$

$x=-2$ or $x=\frac{-5}{3}$

2) $25x(x+1)=-4$

$25x^2+25x+4=0$

$=\frac{-25\pm \sqrt{(25{)}^2-4(25\left)\right(4)}}{2\left(25\right)}$

$=\frac{-25\pm 15}{50}$

$x=\frac{-4}{5}$ or $x=\frac{-1}{5}$.