B
given f(x) in factored form, equate to zero for x-intercepts
(x - 8)(x - 4) = 0, hence
x = 4, x = 8 ← x- intercepts
The vertex lies on the axis of symmetry which is situated at the midpoint of the x- intercepts
x- coordinate of vertex = 
= 6
f(6) = (6 - 8 )(6 - 4 ) = -2 × 2 = - 4 ← y-coordinate
vertex = (6, - 4 ) → B
First find the mean (sum divided by number of values)
4+5+8+10+15=42
42/5=8.4
Then find the difference between each of the numbers and the mean.
4.4, 3.4, 0.4, 1.6, 6.6
Then find the mean of those values.
4.4+3.4+0.4+1.6+6.6=16.4
16.4/5=3.28
Final answer: 3.28
(-1-3i)(-6-i)
=6+i+18i+3i^2
=3i^2+19i+6. Hope it help!
40x - 24 - 33x - 77 = 102
40x - 33x = 102 + 24 + 77
7x = 203
x = 29
