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3 years ago

The prices of two radios are in the ratio x:y

Mathematics

2 answers:

kobusy [5.1K]3 years ago

4 0

Answer:

4:1

Step-by-step explanation:

2(x+20) = 5(y+20)

2x + 40 = 5y + 100

2x - 5y = 60

1(x-5) = 5(y-5)

x - 5 = 5y - 25

x - 5y = -20

x = 80 (solve the two equations simultaneously)

80 - 5y = -20

5y = 100

y = 20

x:y = 80:20

x:y = 4:1

PolarNik [594]3 years ago

3 0

Answer:

x : y = 4 : 1

Step-by-step explanation:

(x+20) : (y+20) = 5 : 2 and (x-5) : (y-5) = 5 : 1

When we multiply the outer and inner members we get:

2x+40 = 5y+100 and x-5 = 5y-25

When we arrange the both equations we get:

2x-5y = 60 and x-5y = -20

When we subtract second equation from the first we get:

x = 80 Now we will replace x=80 in the second equation and get:

80-5y = -20 => -5y= -20-80 => -5y= - 100

Now we will multiply the both sides with number (-1) and get:

5y= 100 => y= 100/5 = 20 => y=20

x : y = 80 : 20 => x : y = 4 : 1

God with you!!!

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Alexis buys groceries using her credit card her card has an APR of 19.99% and she must pay at least 5% of the balance at the end

avanturin [10]

Answer:

The answer is that she would pay $65.56 in finance charges at the end of the month.

Step-by-step explanation:

Given: APR = 19.99%

Carry Over Balance: $398.97

The APR or Annual Percentage Rate, is calculated daily. You will need to get the daily periodic rate, or DPR, so divide the APR by 365:

19.99% = .1999

.1999 / 365 = .005477 (This is the Approximate DPR, rounded up to .005477)

To get the finance charge, multiply the average daily balance by the DPR and then by 30 days:

398.97 * .005477 * 30 = $65.56 finance charge for this carry over balance, at the end of the month. This assumes that the balance is the average daily balance.

Hope this helps!! Have a great day!

7 0

3 years ago

A survey of 865 voters in one state reveals that 408 favor approval of an issue before the legislature. Construct the 95% confid

katrin [286]

Answer:

The 95% confidence interval for the true proportion of all voters in the state who favor approval is (0.4384, 0.5050).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 865, \pi = \frac{408}{865} = 0.4717$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4717 - 1.96\sqrt{\frac{0.4717*0.5283}{865}} = 0.4384$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4717 + 1.96\sqrt{\frac{0.4717*0.5283}{865}} = 0.5050$

The 95% confidence interval for the true proportion of all voters in the state who favor approval is (0.4384, 0.5050).

6 0

3 years ago

What is the product of the polynomials shown below?

Sindrei [870]

Answer:

B. 14x^3+39x^2+18x+20

Step-by-step explanation:

Given polynomials are:

$(7x^2+2x+4)(2x+5)\\For\ product\\(2x+5)(7x^2+2x+4)\\= 2x(7x^2+2x+4)+5(7x^2+2x+4)\\= 14x^3+4x^2+8x+35x^2+10x+20\\Combining\ alike\ terms\\= 14x^3+4x^2+35x^2+8x+10x+20\\=14x^3+39x^2+18x+20$