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3 years ago

Find the solution of this system of equations x - 4y = 31, -x + 3y = -25

Mathematics

1 answer:

Viktor [21]3 years ago

4 0

This is the solution

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At a sale this week, a sofa is being sold for $272. This is a 36% discount from the original price. What is the original price?

Gwar [14]

Answer:

Step-by-step explanation:

A 36% discount means the selling price is (100-36)% = 64% of the original price.

$272 = 64% of x = 0.64·x

x = $272/0.64 = $425

5 0

3 years ago

Can I get help on 4 and 5

Fiesta28 [93]

1.25x2=2.50
2.50x2=5.00
Total-7.50
20.00-7.50=12.50

7 0

3 years ago

What is 16-14 dealing with intergers

fenix001 [56]

16 - 14 = 2

Think of it as in objects. You have 16 candies, and you eat 14. How many do you have left? You can count it and see. You have 2 left. So 16 - 14 = 2

Hope that helps :)

3 0

3 years ago

Read 2 more answers

A geometric sequence is defined by the equation an = (3)3 − n.

Delvig [45]

PART A

The geometric sequence is defined by the equation

$a_{n}=3^{3-n}$

To find the first three terms, we put n=1,2,3

When n=1,

$a_{1}=3^{3-1}$

$a_{1}=3^{2}$

$a_{1}=9$
When n=2,

$a_{2}=3^{3-2}$
$a_{2}=3^{1}$

$a_{2}=3$

When n=3

$a_{3}=3^{3-3}$

$a_{3}=3^{0}$
$a_{1}=1$
The first three terms are,

$9,3,1$

PART B

The common ratio can be found using any two consecutive terms.

The common ratio is given by,
$r= \frac{a_{2}}{a_{1}}$
$r = \frac{3}{9}$

$r = \frac{1}{3}$

PART C

To find
$a_{11}$

We substitute n=11 into the equation of the geometric sequence.

$a_{11} = {3}^{3 - 11}$

This implies that,

$a_{11} = {3}^{ - 8}$

$a_{11} = \frac{1}{ {3}^{8} }$

$a_{11}=\frac{1}{6561}$

4 0

3 years ago

A mattress store sells only king, queen and twin-size mattresses. Sales records at the store indicate that the number of queen-s

Nitella [24]

Answer:

The probability that the next mattress sold is either king or queen-size is P=0.8.

Step-by-step explanation:

We have 3 types of matress: queen size (Q), king size (K) and twin size (T).

We will treat the probability as the proportion (or relative frequency) of sales of each type of matress.

We know that the number of queen-size mattresses sold is one-fourth the number of king and twin-size mattresses combined. This can be expressed as:

$P_Q=\dfrac{P_K+P_T}{4}\\\\\\4P_Q-P_K-P_T=0$

We also know that three times as many king-size mattresses are sold as twin-size mattresses. We can express that as:

$P_K=3P_T\\\\P_K-3P_T=0$

Finally, we know that the sum of probablities has to be 1, or 100%.

$P_Q+P_K+P_T=1$

We can solve this by sustitution:

$P_K=3P_T\\\\4P_Q=P_K+P_T=3P_T+P_T=4P_T\\\\P_Q=P_T\\\\\\P_Q+P_K+P_T=1\\\\P_T+3P_T+P_T=1\\\\5P_T=1\\\\P_T=0.2\\\\\\P_Q=P_T=0.2\\\\P_K=3P_T=3\cdot0.2=0.6$

Now we know the probabilities of each of the matress types.

The probability that the next matress sold is either king or queen-size is:

$P_K+P_Q=0.6+0.2=0.8$

8 0

3 years ago