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3 years ago

What is the value of x in the equation 2x + 3y = 36, when y = 6? 8 9 27 36

Mathematics

2 answers:

Nimfa-mama [501]3 years ago

5 0

Answer:

x = 9

Step-by-step explanation:

we can plug in the given value for y into the equation to find x

2x + 3y = 36

2x + 3(6) = 36

2x + 18 = 36

2x = 18

x = 9

IrinaK [193]3 years ago

4 0

Answer:

x = 9

Step-by-step explanation:

2x + 3y = 36

Let y=6

2x+3(6) = 36

2x+18 = 36

Subtract 18 from each side

2x+18-18 =36-18

2x = 18

Divide by 2

2x/2 =18/2

x = 9

You might be interested in

How many ways can you select and arrange 5 books on a shelf out 13 books?

ololo11 [35]

Answer:

There are 154,440 ways.

Step-by-step explanation:

The word arrange means that the order in which the books are placed is important, which means that the permutations formula is used to solve this question.

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

$P_{(n,x)} = \frac{n!}{(n-x)!}$

In this question:

5 books from a set of 13. So

$P_{(13,5)} = \frac{13!}{(13-5)!} = 154440$

There are 154,440 ways.

8 0

3 years ago

there is 1 litre of tea in a teapot, alex pours 275ml of the tea into a cup what percentage of the tea has alex poured

Nuetrik [128]

Answer:

27.5%

Step-by-step explanation:

Given:

1 Liter In Teapot
Alex poured 275 milliliters of the tea into a cup

Review:

1,000 Milliliters = 1 Liter

Concepts:

A liter is a noun meaning a unit of capacity redefined in 1964 by a reduction of 28 parts in a million to be exactly equal to one cubic decimeter. It is equivalent to 1.0567 U.S. liquid quarts and is equal to the volume of 1 kilogram of distilled water at 4°C.

A millimeter is a noun meaning a unit of capacity equal to one thousandth of a liter, and equivalent to 0.033815 fluid ounce, or 0.061025 cubic inch.

Formula:

The mℓ to ℓ formula is [L] = [mL] / 1000.

Now we must convert 275 milliliters to liters.

1. Divide the volume by 1,000.

275 ÷ 1000 = 0.275

2. Add the Unit Symbol for Liter.

0.275 ⇒ 0.275 L

Now we have to find how much of 1 liter- 0.275 liters as a percentage is.

To convert 0.275 to percent multiply 0.275 by 100. The result is 27.5 percent, or, using the percent sign, 27.5 %.

7 0

1 year ago

The boundary of the lawn in front of a building is represented by the parabola . The parabola is represented on the coordinate p

Colt1911 [192]

The boundary of the lawn in front of a building is represented by the parabola

y = (x^2) /16 + x - 2

And you have three questions which require to find the focus, the vertex and the directrix of the parabola.

Note that it is a regular parabola (its symmetry axis is paralell to the y-axis).

1) Focus:

It is a point on the symmetry axis => x = the x-component of the vertex) at a distance equal to the distance between the directrix and the vertex).

In a regular parabola, the y - coordinate of the focus is p units from the y-coordinate of the focus, and p is equal to 1/(4a), where a is the coefficient that appears in this form of the parabola's equation: y = a(x - h)^2 + k (this is called the vertex form)

Then we will rearrange the standard form, (x^2)/16 + x - 2 fo find the vertex form y = a(x-h)^2 + k

What we need is to complete a square. You can follow these steps.

1) Extract common factor 1/16 => (1/16) [ (x^2) + 16x - 32]

2) Add (and subtract) the square of the half value of the coefficent ot the term on x =>

16/2 = 8 => add and subtract 8^2 => (1/16) [ (x^2) + 16 x + 8^2 - 32 - 8^2]

3) The three first terms inside the square brackets are a perfect square trinomial: =>

(1/16) [ (x+8)^2 - 32 - 64] = (1/16) [ (x+8)^2 - 96] =>

(1/16) [(x+8)^2 ] - 96/16 =>

(1/16) (x +8)^2 - 6

Which is now in the form a(x - h)^2 + k, where:

a = 1/16 , h = - 8, and k = -6

(h,k) is the vertex: h is the x-coordinate of the vertex, and k is the y-coordinate of the vertex.

=> a = 1/16 => p =1/4a = 16/4 = 4

y-componente of the focus = -6 + 4 = -2

x-component of the focus = h = - 8

=> focus = (-8, -2)

2) Vertex

We found it above, vertex = (h,k) = (-8,-6)

3) Directrix

It is the line y = p units below the vertex = > y = -6 - 4 = -10

y = -10

4 0

3 years ago

A photoconductor film is manufactured at a nominal thickness of 25 mils. The product engineer wishes to increase the mean speed

AURORKA [14]

Answer:

A 98% confidence interval estimate for the difference in mean speed of the films is [-0.042, 0.222].

Step-by-step explanation:

We are given that Eight samples of each film thickness are manufactured in a pilot production process, and the film speed (in microjoules per square inch) is measured.

For the 25-mil film, the sample data result is: Mean Standard deviation 1.15 0.11 and For the 20-mil film the data yield: Mean Standard deviation 1.06 0.09.

Firstly, the pivotal quantity for finding the confidence interval for the difference in population mean is given by;

P.Q. = $\frac{(\bar X_1 -\bar X_2)-(\mu_1- \mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ~ $t__n_1_+_n_2_-_2$

where, $\bar X_1$ = sample mean speed for the 25-mil film = 1.15

$\bar X_1$ = sample mean speed for the 20-mil film = 1.06

$s_1$ = sample standard deviation for the 25-mil film = 0.11

$s_2$ = sample standard deviation for the 20-mil film = 0.09

$n_1$ = sample of 25-mil film = 8

$n_2$ = sample of 20-mil film = 8

$\mu_1$ = population mean speed for the 25-mil film

$\mu_2$ = population mean speed for the 20-mil film

Also, $s_p =\sqrt{\frac{(n_1-1)s_1^{2}+ (n_2-1)s_2^{2}}{n_1+n_2-2} }$ = $\sqrt{\frac{(8-1)\times 0.11^{2}+ (8-1)\times 0.09^{2}}{8+8-2} }$ = 0.1005

Here for constructing a 98% confidence interval we have used a Two-sample t-test statistics because we don't know about population standard deviations.

So, 98% confidence interval for the difference in population means, ( $\mu_1-\mu_2$ ) is;

P(-2.624 < $t_1_4$ < 2.624) = 0.98 {As the critical value of t at 14 degrees of

freedom are -2.624 & 2.624 with P = 1%}

P(-2.624 < $\frac{(\bar X_1 -\bar X_2)-(\mu_1- \mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ < 2.624) = 0.98

P( $-2.624 \times {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ < $2.624 \times {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ < ) = 0.98

P( $(\bar X_1-\bar X_2)-2.624 \times {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ < ( $\mu_1-\mu_2$ ) < $(\bar X_1-\bar X_2)+2.624 \times {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ) = 0.98

98% confidence interval for ( $\mu_1-\mu_2$ ) = [ $(\bar X_1-\bar X_2)-2.624 \times {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ , $(\bar X_1-\bar X_2)+2.624 \times {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ]

= [ $(1.15-1.06)-2.624 \times {0.1005 \times \sqrt{\frac{1}{8}+\frac{1}{8} } }$ , $(1.15-1.06)+2.624 \times {0.1005 \times \sqrt{\frac{1}{8}+\frac{1}{8} } }$ ]

= [-0.042, 0.222]

Therefore, a 98% confidence interval estimate for the difference in mean speed of the films is [-0.042, 0.222].

Since the above interval contains 0; this means that decreasing the thickness of the film doesn't increase the speed of the film.

7 0

2 years ago

A grocer bought n eggs at $x each. He marked up the price of each egg by $y and sold all of them. Find the sales amount, express

Alex777 [14]

Answer:

Sales = n $\times$ ($x + $y)

Step-by-step explanation:

The basic simple sales equation is

Quantity $\times$ Price = Sales

Here in the given question,

Total quantity of sales = n

Price = Cost + markup

(Markup refers to the profit added to cost)

Thus price = $x (cost) + $y (markup)

Sales = n $\times$ ($x + $y)

Sales amount is the total amount received from sales of products, total quantity at some price provided.

4 0

3 years ago