Question

3x^2+5x-12 solved by using quadratic formula

Answer 1

Answer:

$x = \dfrac{4}{3}$   or   $x = -3$

Step-by-step explanation:

3x^2 + 5x - 12

To solve it, you need an equation, so I think you mean this equation.

3x^2 + 5x - 12 = 0

Using the quadratic formula, you have a = 3, b = 5, c = -12.

$x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

$x = \dfrac{-5 \pm \sqrt{5^2 - 4(3)(-12)}}{2(3)}$

$x = \dfrac{-5 \pm \sqrt{25 + 144}}{6}$

$x = \dfrac{-5 \pm \sqrt{169}}{6}$

$x = \dfrac{-5 \pm 13}{6}$

$x = \dfrac{8}{6}$   or   $x = \dfrac{-18}{6}$

$x = \dfrac{4}{3}$   or   $x = -3$