Which shows the correct substitution of the values [tex]\( a, b, \)[/tex] and [tex]\( c \)[/tex] from the equation [tex]\( 0 = -3x^2 - 2x + 6 \)[/tex] into the quadratic formula?

Quadratic formula: [tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]

A. [tex]\[ x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(-3)(6)}}{2(-3)} \][/tex]

B. [tex]\[ x = \frac{-2 \pm \sqrt{2^2 - 4(-3)(6)}}{2(-3)} \][/tex]

C. [tex]\[ x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(3)(6)}}{2(3)} \][/tex]

D. [tex]\[ x = \frac{-2 \pm \sqrt{2^2 - 4(3)(6)}}{2(3)} \][/tex]



Answer :

To solve the quadratic equation [tex]\( 0 = -3x^2 - 2x + 6 \)[/tex] using the quadratic formula, we need to identify the coefficients [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex] from the equation in the form [tex]\( ax^2 + bx + c = 0 \)[/tex].

Here, we have:
- [tex]\( a = -3 \)[/tex]
- [tex]\( b = -2 \)[/tex]
- [tex]\( c = 6 \)[/tex]

The quadratic formula is:
[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]

Substituting the given values of [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex] into the formula:

1. Substitute [tex]\( b = -2 \)[/tex]:
[tex]\[ x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(-3)(6)}}{2(-3)} \][/tex]

This simplifies to:
[tex]\[ x = \frac{2 \pm \sqrt{4 + 72}}{-6} \][/tex]

Then,
[tex]\[ x = \frac{2 \pm \sqrt{76}}{-6} \][/tex]

So the correct substitution of [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex] in the quadratic formula is:
[tex]\[ x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(-3)(6)}}{2(-3)} \][/tex]

This matches:
[tex]\[ x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(-3)(6)}}{2(-3)} \][/tex]

This shows the correct substitution of the values [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex] from the equation [tex]\( 0 = -3x^2 - 2x + 6 \)[/tex] into the quadratic formula.