Question

Solve: $5x^2=4x+7$

Answer 1

Given eq. is $5x^2=4x+7$

$\Rightarrow 5x^2-4x-7=0$

$\therefore x=\frac{+4\pm \sqrt{(-4{)}^2-4(5\left)\right(-7)}}{2\times 5}$

$\frac{4\pm \sqrt{16+140}}{10}$

$\frac{4\pm \sqrt{156}}{10}$

$\frac{4\pm 2\sqrt{39}}{10}$

$\frac{2\pm 2\sqrt{39}}{5}$

$\therefore$ roots are $\frac{2+2\sqrt{39}}{5},\frac{2-2\sqrt{39}}{5}$