Question

The some of the roots of 2x 2 + 8x - 3 = 0 is

Answer 1

`x= \frac{-b \pm \sqrt{ b^(2) -4ac} }{2a}`; where a = 2, b = 8 and c = -3

`x= \frac{-8 \pm \sqrt{ 8^(2) -4 * 2 * -3} }{2 * 2} \\ x= (-8 \pm √( 64 +24) )/(4) \\ x= (-8 \pm √( 88) )/(4) \\ x= (-8 \pm 2√( 22) )/(4) \\ x= (-4 + √( 22) )/(2)\ or\ (-4 - √( 22) )/(2)`
The sum of the roots is
`(-4 + √( 22) )/(2)+ (-4 - √( 22) )/(2) \\ = (-8)/(2) = -4`
OR
simply sum of roots = -b/a = -8/2 = -4