30. The equation below represents the quadratic function where a and b are constants. If the function is graphedin the coordinate plane, its vertex

30. The equation below represents the quadratic function where a and b are constants. If the function is graphed in the coordinate plane, its vertex is at the point (2.-54). What is the value of a + b?
f(x) = a(x + b)(x-8)
A 4
B. 3.3
C. 6
D. 73

9. Find the area of a circle having a circumference of 382. Round to the nearest tenth. Use 3.14 for 1. a. 1133.5 units b. 1078.6

1. Expert says:

hello from mrbilldoesmath!

discussion:

factor x out of the equation:

x^3 + 12x^2 + 36x = x (x^2 + 12x + 36).

note that 6+6 = 12 and 6*6 = 36 so the above factors into:

x (x+6)^2

which is choice b

you,

mrb

2. Expert says:

step-by-step explanation:

3. Expert says:

nkcoicjc

4. Expert says:

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm