Question

Solve: $4n^2+5n-636=0$

Answer 1

Given: $4n^2+5n-636=0$

Using quadratic formula, we get,

$\Rightarrow x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$\Rightarrow x=\frac{-5\pm \sqrt{(5{)}^2-4(4\left)\right(-636)}}{2\left(4\right)}$

$=\frac{-5\pm \sqrt{25+10176}}{8}$

$=\frac{-5\pm \sqrt{10201}}{8}$

$=\frac{-5\pm 101}{8}$

$\Rightarrow x=\frac{-5+101}{8}$ or $x=\frac{-5-101}{8}$

$\Rightarrow x=\frac{96}{8}$ or $x=\frac{-106}{8}$

$\therefore x=12,\frac{-53}{4}$