Question

Which shows the correct substitution of the values a, b, and c from the equation –2 = –x + x2 – 4 into the quadratic formula? Quadratic formula: x =

Answer 1

Answer:

The answer in the procedure

Step-by-step explanation:

we have

$2=-x+x^{2} -4$

$x^{2}-x-4-2=0$

$x^{2}-x-6=0$

we know that

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$x^{2}-x-6=0$

so

$a=1\\b=-1\\c=-6$

substitute in the formula

$x=\frac{-(-1)(+/-)\sqrt{(-1)^{2}-4(1)(-6)}} {2(1)}$

$x=\frac{1(+/-)\sqrt{25}} {2}$

$x=\frac{1(+/-)5} {2}$

$x=\frac{1(+)5} {2}=3$

$x=\frac{1(-)5} {2}=-2$