Question

Solve the following quadratic equation by formula method:

3m² − m − 10 = 0

Answer 1

Given: 3m² − m − 10 = 0

Comparing with standard form

ax² + bx + c = 0

a = 3, b = −1, c = −10

D = b² − 4ac

= (−1)2 − 4(3) (−10)

= 1 − 12 (−10)

= 1 + 120

= 121 > 0

By formula method,

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

`m = (- (-1) +- sqrt(121))/(2(3))`

`m = (1 +- sqrt(121))/6`

`m = (1 +- 11)/6`

`m = (1 + 11)/6 or m = (1 - 11)/6`

`m = 12/6 or m = (-10)/6`

m = 2 or `m = (-5)/3`

The roots of the quadratic equation are m = 2 or `m = (-5)/3`