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4 years ago

Y= 3x - 15 x+y=13 find the solution

Mathematics

2 answers:

Pepsi [2]4 years ago

6 0

Answer:

x+3x-15=13

4x=28

x=7

......

vfiekz [6]4 years ago

5 0

Answer:

$y = 3x - 15 \\ \\ to \: find \: x \: substitute \: y \: into \: 0\\ \\ 0 = 3x - 15 \\ - 3x = - 15 \\ divide \: both \: sides \:by \: - 3 \\ \\ x = 5$

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1 load of bricks weigh twice as much as a load of sticks. the total weight of 4 loads of each is 771 kg. What is the total weigh

liq [111]

X=brick y=sticks
x=2y
4x+4y=771
4(2y)+4y=771
8y+4y=771
12y=771
y= 771/12
y = 64.25
x = 64.25*2=128.5

Answer:
128.5+64.25*3=321.25kg

7 0

4 years ago

Find the coefficient of x of (1+2/x²) (2x-3/x)⁵

jenyasd209 [6]

First, we have

(1 + 2/x²) (2x - 3/x)⁵ = (2x - 3/x)⁵ + 2/x² (2x - 3/x)⁵

In the expansion of (2x - 3/x)⁵, there is no x² term. Each term takes the form

$c (2x)^{5 - i} \left(-\dfrac3x\right)^i$

where c is a binomial coefficient, and i is taken from the range {0, 1, 2, 3, 4, 5}. Looking at just the power of x in the product, we have

$x^{5 - i} \left(\dfrac1x\right)^i = x^{5 - 2i}$

and 5 - 2i = 1 only if i = 2. By the binomial theorem, this term is given by

$\dbinom52 (2x)^{5-2} \left(-\dfrac3x\right)^2 = \dfrac{5!}{2!(5-2)!} \cdot 2^3 \cdot (-3)^2 x = 720x$

In the other expansion, we have an additional factor of 1/x², so that any given them in the expansion contains a power of x of the form

$\dfrac1{x^2} x^{5 - i} \left(\dfrac1x\right)^i = x^{3 - 2i}$

and 3 - 2i = 1 only if x = 1. This term in the expansion is

$\dfrac2{x^2} \dbinom51 (2x)^{5-1} \left(-\dfrac3x\right)^1 = \dfrac{5!}{1!(5-1)!} \cdot 2^5 \cdot (-3)^1 x = -480x$

Then the coefficient of the x term in the whole expansion is 720 - 480 = 240.

8 0

3 years ago

Please help me asap

Komok [63]

Answer:

answer is c

Step-by-step explanation:

6 0

3 years ago

On a certain hot summer day, 481 people used the public swimming pool. The daily prices are 1.25 for children and 2.25 for adult

spayn [35]

Answer:the number of children that swam in the public pool that day is 222

the number of adult that swam in the public pool that day is 259

Step-by-step explanation:

Let x represent the number of children that swam in the public pool that day.

Let y represent the number of adult that swam in the public pool that day.

On a certain hot summer day, 481 people used the public swimming pool. This means that

x + y = 481

The daily prices are 1.25 for children and 2.25 for adults. The receipts for admission totaled to 86.25. This means that

1.25x + 2.25y = 860.25 - - - - - - - -1

Substituting x = 481 - y into equation 1, it becomes

1.25(481 - y) + 2.25y = 860.25

601.25 - 1.25y + 2.25y = 860.25

- 1.25y + 2.25y = 860.25 - 601.25

y = 259

Substituting y = 259 into x = 481 - y, it becomes

x = 481 - 259

x = 222

8 0

4 years ago

The daily revenue at a university snack bar has been recorded for the past five years. Records indicate that the mean daily reve

faltersainse [42]

Answer: 0.9938

Step-by-step explanation:

Let x be the random variable that represents the daily revenue at a university snack bar.

As per given , we have

$\mu=2700$ , $\sigma=400$ and n= 100

Using formula $z=\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}$ ,

z-score for x= 2600

$z=\dfrac{2600-2700}{\dfrac{400}{\sqrt{100}}}=-2.5$

The probability that the average daily revenue of the sample is higher than $2600 :

$P(x>2600)=P(z>-2.5)=P(z$ [P(Z>-z)=P(Z<z)]

$=0.9937903\approx0.9938$

Therefore, the probability that the average daily revenue of the sample is higher than $2600 = 0.9938

8 0

3 years ago