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

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`