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3 years ago

When solving using Elimination:

Mathematics

1 answer:

Zielflug [23.3K]3 years ago

6 0

Answer:

Multiply 1st equation by -4

Step-by-step explanation:

Multiply the 1stequation by-4

-20x+8y=-44. Leave 2nd equation

8x-8y=-16

See how the 8y cancels with -8y

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If a polygon has an interior angle of 144, what kind of polygon is it? (find the # of sides first

ikadub [295]

Each Interior Angle = ((Number of Sides -2) • 180 degrees) ÷ (Number of Sides)

Solving for number of sides

Each Interior Angle / 180 = (N -2) / (N)

144 / 180 = (n-2) / n

144 * n = 180n -360
360 = 36 n

n = 10 the number of sides

Source:
http://www.1728.org/polygon.htm

5 0

3 years ago

The Resource Conservation and Recovery Act mandates the tracking and disposal of hazardous waste produced at U.S. facilities. Pr

aniked [119]

Answer:

(a) $E(X) = 0.383$

The expected number in the sample that treats hazardous waste on-site is 0.383.

(b) $P(x = 4) = 0.000169$

There is a 0.000169 probability that 4 of the 10 selected facilities treat hazardous waste on-site.

Step-by-step explanation:

Professional Geographer (Feb. 2000) reported the hazardous waste generation and disposal characteristics of 209 facilities.

N = 209

Only eight of these facilities treated hazardous waste on-site.

r = 8

a. In a random sample of 10 of the 209 facilities, what is the expected number in the sample that treats hazardous waste on-site?

n = 10

The expected number in the sample that treats hazardous waste on-site is given by

$E(X) = \frac{n \times r}{N}$

$E(X) = \frac{10 \times 8}{209}$

$E(X) = \frac{80}{209}$

$E(X) = 0.383$

Therefore, the expected number in the sample that treats hazardous waste on-site is 0.383.

b. Find the probability that 4 of the 10 selected facilities treat hazardous waste on-site

The probability is given by

$P(x = 4) = \frac{\binom{r}{x} \binom{N - r}{n - x}}{\binom{N}{n}}$

For the given case, we have

N = 209

n = 10

r = 8

x = 4

$P(x = 4) = \frac{\binom{8}{4} \binom{209 - 8}{10 - 4}}{\binom{209}{10}}$

$P(x = 4) = \frac{\binom{8}{4} \binom{201}{6}}{\binom{209}{10}}$

$$ P(x = 4) = \frac{70 \times 84944276340}{35216131179263320}$

$P(x = 4) = 0.000169$

Therefore, there is a 0.000169 probability that 4 of the 10 selected facilities treat hazardous waste on-site.

8 0

3 years ago

At the beginning of an experiment, the number of bacteria in a colony was counted at time t=O. The number of bacteria in the col

yan [13]

Answer:

1092

Step-by-step explanation:

We have been given that the number of bacteria in the colony t minutes after the initial count modeled by the function $B(t)=9(3)^t$ . We are asked to find the average rate of change in the number of bacteria over the first 6 minutes of the experiment.