Carry out the mult.: f(x) = -[x^2 - 21x + 9x - 189]
Combine like terms: f(x) = -[x^2 - 12x - 189]
Eliminate the brackets [ ]: f(x) = -x^2 + 12x + 189
Identify coefficients a, b and c: a= -1, b=12, c=189
The equation of the axis of symmetry is x = -b/(2a), which here equals
x = -(12)/[2(-1)], or x = 6
This is also the x-coordinate of the vertex. Plug x=6 into the original equation to calculate the y-coordinate.
#1 7.1 years old
#2 7.8 years old
#3 87.4
#4 74
#5 7.4

=

equals
k = 15.6
First, simplify

to 1.2. Your problem should look like:

= 1.2
Second, multiply both sides by 13. Your problem should look like: k = 15.6, which is the answer.
Answer:
A, D, and E
Step-by-step explanation:
because they are negative
Answer:
the answer is 7.33
Step-by-step explanation:
I used a calculator