Question

x^2 + x -210 =0 use quadratic formula

Answer 1

Given Equation

$\tt \to \: {x}^{2} + x - 210 = 0$

To Find the value of x

Formula

$\tt \to \: x = \dfrac{ - b \pm \sqrt{ {b}^{2} - 4ac } }{2a}$

Now Compare with

$\tt \to \: a {x}^{2} + bx + c = 0$

we get

$\tt \to \: a = 1,b = 1 \: and \: c = - 210$

Put the values on formula

$\tt \to \: x = \dfrac{ - 1 \pm \sqrt{(1) { }^{2} - 4 \times 1 \times ( - 210) } }{2 \times 1}$

$\tt \to \: x = \dfrac{ - 1 \pm \sqrt{1 + 840} }{2}$

$\tt \to \: x = \dfrac{ - 1 \pm \sqrt{841} }{2}$

$\tt \: \to \: x = \dfrac{ - 1 \pm29}{2}$

$\tt \to \: x = \dfrac{ - 1 + 29}{2} \: \: and \: x = \dfrac{ - 1 - 29}{2}$

$\tt \to \:x = \dfrac{28}{2} \: and \: x = \dfrac{ - 30}{2}$

$\tt \to \: x =14 \: \: and \:x= - 15$

Answer

$\tt \to \: x =14 \: \: and \:x= - 15$