x^2+2x∓ 5=0 x= b±√(b^2 4ac)/2a= 2±√(4 4× 1× ( 5))/2× 1 = 2∓√(4+20)/2= 2±√(24)/2= 1±√(6)/2 ∴ x= 1+√(6)/2 or x= 1 √(6)/2 ...

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Solving a Quadratic Equation by Completion of Squares Method

Factorise x2...

Question

Factorise
$x^{2} + 2 x - 5 = 0$

Open in App

Solution

$x^{2} + 2 x \mp 5 = 0$
$x = \frac{- b \pm \sqrt{b^{2} - 4 a c}}{2 a} = \frac{- 2 \pm \sqrt{4 - 4 \times 1 \times (- 5)}}{2 \times 1}$
$= \frac{- 2 \mp \sqrt{4 + 20}}{2} = \frac{- 2 \pm \sqrt{24}}{2} = \frac{- 1 \pm \sqrt{6}}{2}$
$∴ x = \frac{- 1 + \sqrt{6}}{2}$ or $x = \frac{- 1 - \sqrt{6}}{2}$

Suggest Corrections

Similar questions

Factorise: $x^{2} + 6 x + 5$

x^{2} + 7 x + 6

x^{2} + 11 x + 18

x^{2} + 2 x - 8

x^{2} - 4 x - 5

x^{2} - 8 x + 12

x^{2} - 5 x - 24

x^{2} + 2 x - 15

x^{2} + 2 x + 1

x^{2} - 2 x - 15

Join BYJU'S Learning Program