Answer:
B. 236.3
Step-by-step explanation:
Population density can be found by dividing the number of people by the area of the land.
number of people / land area
The population is 20,510 people and the area is 86.8 square miles.
20,510 people / 86.8 square miles
Divide 20,510 by 86.8
236.290323 people /square mile
Round to the nearest tenth. The 9 in the hundredth place tell us to round the 2 to a 3 in the tenth place.
236.3 people/ square mile
There are 236.3 people per square mile and B is correct.
Answer:
y = 1/6 x^2 + 8/3 x + 49/6
Step-by-step explanation:
This is a parabola which opens upwards.
The distance of a point (x, y) from the focus is
√[(x - -8)^2 + (y - -1)^2] and
the distance of the point from the line y = -4
= y - -4
These distances are equal for a parabola so:
√[(x - -8)^2 + (y - -1)^2] = y + 4
Squaring both sides:
(x + 8)^2 + (y + 1)^2 = (y + 4)^2
x^2 + 16x + 64 + y^2 + 2y + 1 = y^2 + 8y + 16
x^2 + 16x + 64 + 1 - 16 = 8y - 2y
6y = x^2 + 16x + 49
y = 1/6 x^2 + 8/3 x + 49/6 is the equation of the parabola.
(12+9x) - (6+3x) + 6x + -3
6+3x + 6x+-3
3+ 9x