Answer:
x=-3.5
reason:
first, add 3 to both sides
this makes the equation -1/2x=7
then, divide both sides by -1/2
this will give you x=-3.5
Answer:
{x,y,z} = {1,-1,-2}
Step-by-step explanation:
Answer:
y = (x + 4.5)² - 13.25
Step-by-step explanation:
y = x² + 9x + 7
We need to get a perfectly squared binomial as part of the right side.
Take the '9x' term, divide it in half, square it, add <u>and also subtract it </u>on the right side, as shown below. That would be (4.5)² = 20.25 added <u>and </u>subtracted.
y = x² + 9x + 7
y = x² + 9x + 20.25 + 7 - 20.25
y = (x² + 9x + 20.25) - 13.25
y = (x + 4.5)² - 13.25
y = (x + 4.5)² - 13.25
Vertex Form is y = a(x-h)² + k, where the parabola vertex is (h, k)
So if you wrote this as y = 1(x - [-4.5] )² + (-13.25), we would see that a = 1, and h = -4.5 and k = -13.25.
Vertex = (-4.5, -13.25)
I verified on a graphing calculator that this is indeed the vertex of the parabola.
Answer:
The secondary attack rate is 55%
Step-by-step explanation:
Total number of students = 83
Primary cases: cases A+B+C = 3 primary cases.
Secondary cases = 44
Total cases = 44 + 3 = 47
To find the secondary attack rate, we are to assume that the primary cases are now immune because they had the illness.
We have:
Secondary attack rate = 
The secondary attack rate is 55%
X² - Sx + P = 0
x² - (-3+2)x + (-3)*2 = 0
x² - (-1)x - 6 = 0
x² + x - 6 = 0
a = 2
2x² + 2x - 12 = 0
