Solve the following system of equations by linear combination:

Mathematics

1 answer:

Sholpan [36]2 years ago

3 0

3d - e =7
d + e = 5
-------------
4d / = 12
d=12:4
d=3

3+e=5
e=5-3
e=2
the solution is (3,2)

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Sonny has $5 to buy pencils and rulers. Pencils are 8 cent each. Rulers are 30 cent each. She says “I will buy 15 pencils. Then

ANEK [815]

Answer:

12 Rulers and 17 Pencils

Step-by-step explanation:

15 x 8 = cents spend

15 x 8 = 120

$5-120cents ($1.2) = $3.8 (380 cents)

380/30= 12 rulers with 20 cent remaining

20/8= 2 pencils with 4 cent remaining

now add!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

12 ruler +2 pencils +15 pencils=

12 Rulers and 17 Pencils

4 0

3 years ago

What is the total area of the prism?

Pavlova-9 [17]

First we look for the area of the triangle which is given by:
A = (1/2) * (4) * (6)
A = 12 feet ^ 2
Area of the rectangles:
Rectangle 1:
R1 = (4) * (8)
R1 = 32 feet ^ 2
Rectangle 2:
R2 = (6) * (8)
R2 = 48 feet ^ 2
Rectangle 3:
R3 = (root (6 ^ 2 + 4 ^ 2)) * (8))
R3 = 57,68882041 feet ^ 2
The total area will be:
A = 2A + R1 + R2 + R3
Substituting values:
A = 2 * (12) + 32 + 48 + 57,68882041
A = 161.6888204 feet ^ 2
Answer:
The total area of the prism is:
A = 161.6888204 feet ^ 2

6 0

2 years ago

A website manager has noticed that during the evening hours, about 5 people per minute check out from their shopping cart and m

Over [174]

Answer:

a) Poisson distribution

b) 99.33% probability that in any one minute at least one purchase is made

c) 0.05% probability that seven people make a purchase in the next four minutes

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

$P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}$

In which

x is the number of sucesses

e = 2.71828 is the Euler number

$\mu$ is the mean in the given time interval.

5 people per minute check out from their shopping cart and make an online purchase.

This means that $\mu = 5$

a) What model might you suggest to model the number of purchases per minute? 

The only information that we have is the mean number of an event(purchases) in a time interval. Each event is also independent fro each other. So you should suggest the Poisson distribution to model the number of purchases per minute.

b) What is the probability that in any one minute at least one purchase is made? 

Either no purchases are made, or at least one is. The sum of the probabilities of these events is 1. So

$P(X = 0) + P(X \geq 1) = 1$