Question

Solve the given quadratic equation by using the formula method:

5x² + 13x + 8 = 0

Answer 1

5x² + 13x + 8 = 0

Comparing with ax² + bx + c = 0

a = 5, b = 13, c = 8

b² − 4ac = (13)² − 4(5)(8)

= 169 − 160

= 9

`x = (-b +- sqrt(b^2 - 4ac))/(2a)`

= `(-13 +- sqrt9)/(2 xx 5)`

= `(-13 +- 3)/10`

∴ x = `(-13 + 3)/10` or x = `(-13 - 3)/10`

∴ x = `(-10)/10` or x = `(-16)/10`

∴ x = −1 or x = `(-8)/5`

∴ Roots are −1 and `(-8)/5`.