30.54 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=
-bt/b² - 4ac
2a

x=1 +or- √(1)-(-8)/-2

Step-by-step explanation:

-2=-x+x^2-4

-2+4= x^2-x

2=x^2-x

x^2-x-2=0

Quadratic formula

x=-b +or -√b^2-4ac/2a

from the equation

a=1

b=-1

c=-2

Insert the variables into the quadratic formula

We have

x=-(-1) +or- √(-1)^2 - 4*(1)*(-2)/-2*(1)

x=1 +or- √(1)-(-8)/-2

=1 +or- √1+8/2

=1 +or-√9/2

=1 +or- 3/2

=1+3/2 or 1-3/2

=4/2 or -2/2

x=2 or -1

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls