Question

Which is the solution set to: 3x^2 + 8x = 3?

{-1/3, 3}


{-1/3, -3}


{1/3, -3}


None of the above


{1/3, 3}

Answer 1

`\frac {1}{3} \: \: and \: - 3`

Explanation:

`3 {x}^(2) + 8x = 3`

`3 {x}^(2) + 8x - 3 = 0`

`d = {b}^(2) - 4ac = {8}^(2) - 4 * 3 * ( - 3) = 64 + 36 = 100 > 0`

`x1 = ( - b - √(d) )/(2a) = ( - 8 - 10)/(2 * 3) = ( - 18)/(6) = - 3`

`x2 = ( - b + √(d) )/(2a) = ( - 8 + 10)/(6) = (2)/(6) = (1)/(3)`