Question

Solve the following quadratic equation:

5x² + 13x + 8 = 0

Answer 1

We write, 13x = 5x + 8x as 5x² × 8 = 40x² = 5x × 8x 

∴ 5x² + 13x + 8 = 0 

⇒ 5x² + 5x + 8x + 8 = 0 

⇒ 5x(x + 1) + 8(x + 1) = 0

⇒ (x + 1) (5x + 8) = 0 

⇒ x + 1 = 0 or 5x + 8 = 0 

⇒ x = –1 or x = `(-8)/5` 

Hence, –1 and `(-8)/5` are the roots of the given equation.