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 =

Question

asked May 23, 2020 86.2k views

1 Answer

Mikek · Answer 1 · 2020-05-28T13:34:31+0000

Answer:

The answer in the procedure

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

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

$x=\frac{1(+/-)√(25)} {2}$

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

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

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