The sum of three consecutive odd integers is 153. what is the value of the largest of the integers?

DIA [1.3K]

I'm only going to alter the left hand side. The right side will stay the same the entire time

I'll use the identity tan(x) = sin(x)/cos(x) and cot(x) = cos(x)/sin(x)
I'll also use sin(x+y) = sin(x)cos(y)+cos(x)sin(y) and cos(x+y) = cos(x)cos(y)-sin(x)sin(y)

So with that in mind, this is how the steps would look:

tan(x+pi/2) = -cot x
sin(x+pi/2)/cos(x+pi/2) = -cot x
(sin(x)cos(pi/2)+cos(x)sin(pi/2))/(cos(x)cos(pi/2)-sin(x)sin(pi/2)) = -cot x
(sin(x)*0+cos(x)*1)/(cos(x)*0-sin(x)*1) = -cot x
(0+cos(x))/(-sin(x)-0) = -cot x
(cos(x))/(-sin(x)) = -cot x
-cot x = -cot x

Identity is confirmed

6 0

3 years ago

A spool contains 270 inches of wire. How many pieces of wire, each with the a length of 1 7/8 inches, can be cut from the spool?

prisoha [69]

You would be able to cut 144 pieces of wire from the spool because 270/1 7/8 (or 1.875) equals 144

6 0

3 years ago

Solve x^3 = 1/8 Is it 1/2, +1/2, 1/4 or + 1/4 ( area and square roots)

k0ka [10]

Answer:

Step-by-step explanation:

x^3 = 1/8

Taking the cube of both side

x^3 = 1/(2)^3

(x)^3 = (1/2)^3

Eliminate ^3 from both sides

x = 1/2

8 0

3 years ago

Solve the system:<br> 2.5(x−3y)−3=−3x+0.5 3(x+6y)+4=9y+19

Aleksandr-060686 [28]

Answer:

The value of x and y that satisfy the equations is x = 2 and y = 1

Step-by-step explanation:

Given

2.5(x−3y)−3=−3x+0.5

3(x+6y)+4=9y+19

Required.

Find x and y

We start by opening all brackets

2.5(x−3y)−3=−3x+0.5 becomes

2.5x - 7.5y - 3 = -3x + 0.5

Collect like terms

2.5x + 3x - 7.5y = 3 + 0.5

5.5x - 7.5y = 3.5 ---- Equation 1

In similar vein, 3(x+6y)+4=9y+19 becomes

3x + 18y + 4 = 9y + 19

Collect like terms

3x + 18y - 9y = 19 - 4

3x + 9y = 15

Multiply through by ⅓

⅓ * 3x + ⅓ * 9y = ⅓ * 15

x + 3y = 5

Make x the subject of formula

x = 5 - 3y

Substitute 5 - 3y for x in equation 1

5.5(5 - 3y) - 7.5y = 3.5

27.5 - 16.5y - 7.5y = 3.5

27.5 - 24y = 3.5

Collect like terms

-24y = 3.5 - 27.5

-24y = -24

Divide through by - 24

y = 1

Recall that x = 5 - 3y.

Substitute 1 for y in this equation

x = 5 - 3(1)

x = 5 - 3

x = 2

Hence, x = 2 and y = 1

3 0

3 years ago

A report on consumer financial literacy summarized data from a representative sample of 1,664 adult Americans. Based on data fro

daser333 [38]

Answer:

a. The 95% confidence interval for the proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is (0.54, 0.588). This means that we are 95% sure that the true proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is between these two bounds.

b. Because this confidence interval is entirely above 0.5, the interval is consistent with the statement that a majority of adult Americans would give themselves a grade of A or B.

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 $1 - \frac{\alpha}{2}$ .

Sample of 1,664 adult Americans, 939 people in the sample would have given themselves a grade of A or B in personal finance.

This means that $n = 1664, \pi = \frac{939}{1664} = 0.5643$

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:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5643 - 1.96\sqrt{\frac{0.5643*0.4357}{1644}} = 0.54$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5643 + 1.96\sqrt{\frac{0.5643*0.4357}{1644}} = 0.588$

The 95% confidence interval for the proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is (0.54, 0.588). This means that we are 95% sure that the true proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is between these two bounds.

(b) Is the confidence interval from part (a) consistent with the statement that a majority of adult Americans would give themselves a grade of A or B?

Yes, because the confidence interval is entirely above 0.5.

Because this confidence interval is entirely above 0.5, the interval is consistent with the statement that a majority of adult Americans would give themselves a grade of A or B.

8 0

3 years ago