Question

Please help with this

Answer 1

Answer:

D) x=$\frac{-2+-2\sqrt{7} }{3}$

Step-by-step explanation:

The quadratic formula is : $\frac{-b+-\sqrt{b^2-4ac} }{2a}$

A in terms of this question=9

B in terms of the question is 12

C in terms of the question is -24.

This question is an example of a quadratic equation. To work this out you may first need a calculator. The first step is to substitute the values of a,b and c into the formula.  So once substituted the formula of $\frac{-b+-\sqrt{b^2-4ac} }{2a}$ becomes $\frac{(-12)+-\sqrt{(12)^2-4*(9)*(-24)} }{2(9)}$. Although when written in a calculator there will not be a plus and minus button and so you would have to do this separately.

However when substituting the values it would be best practice to put them in brackets.

1) Substitute the values into the equation for +.

$\frac{(-12)+\sqrt{(12)^2-4*(9)*(-24)} }{2(9)}=\frac{-2+2\sqrt{7} }{3} /1.097167541$

2) Substitute the values into the equation for -.

$\frac{(-12)-\sqrt{(12)^2-4*(9)*(-24)} }{2(9)}=\frac{-2+2\sqrt{7} }{3} /-2.430500874$