Question

Solve 3x^2 + 6x+15=0

Answer 1

The solution of given equation is ( - 1 + 2 i ) , ( - 1 - 2 i )

Explanation:

Given equation as :

3 x² + 6 x +15 = 0

The value of x fro the quadratic equation a x² + b x + c = 0 is obtained as

x =
`\frac{-b\pm \sqrt{b^(2)-4ac}}{2a}`

So , from given eq , the value of x is now obtain as

x =
`\frac{-b\pm \sqrt{b^(2)-4* a* c}}{2* a}`

Or, x =
`\frac{-6\pm \sqrt{6^(2)-4* 3* 15}}{2* 3}`

Or, x =
`(√(-144) )/(6)`

∴ x = ( - 1 + 2 i ) , ( - 1 - 2 i )

Hence The solution of given equation is ( - 1 + 2 i ) , ( - 1 - 2 i ) Answer