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2 years ago

Solve for x in the equation x squared minus 14 x + 31 = 63.

Mathematics

2 answers:

Bumek [7]2 years ago

8 0

Answer: X = 2.28

Step-by-step explanation:

-31 from both sides (The positive 31 and 63)

= 14x = 32 then divide both sides by 14

14x divided by 14 is x and 32 divided by 14 is like 2.28

x=2.28

algol [13]2 years ago

3 0

X=16 14 times + 31=63

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A lumber yard has a scrap sheet of plywood that is 23 3/4 inches by 41 1/5 inches long what is the area of the plywood?

Sholpan [36]

Answer:

$978\frac{1}{2}\text{ inches}^2$ .

Step-by-step explanation:

We have been given that a lumber yard has a scrap sheet of plywood that is 23 3/4 inches by 41 1/5 inches long.

Since plywood is in shape of rectangle, so to find the area of plywood we will multiply the length of plywood by its width.

$\text{Area of rectangle}=\text{Length*Width}$

$\text{Area of plywood}=23\frac{3}{4}\text{ inches}\times 41\frac{1}{5}\text{ inches}$

Let us convert our mixed fractions into improper fractions.

$\text{Area of plywood}=\frac{95}{4}\text{ inches}\times \frac{206}{5}\text{ inches}$

$\text{Area of plywood}=\frac{95}{4}\times \frac{206}{5}\text{ inches}\times \text{inches}$

Upon cancelling out greatest common factors we will get,

$\text{Area of plywood}=\frac{19}{2}\times 103\text{ inches}^2$

$\text{Area of plywood}=\frac{1957}{2}\text{ inches}^2$

Now let us convert our answer into mixed fraction.

$\text{Area of plywood}=978\frac{1}{2}\text{ inches}^2$

Therefore, the area of plywood is $978\frac{1}{2}\text{ inches}^2$ .

8 0

2 years ago

J.J.Bean sells a wide variety of outdoor equipment and clothing. The company sells both through mail order and via the internet.

melamori03 [73]

Answer:

99% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is [$(-31.82) , $12.02].

Step-by-step explanation:

We are given that a random sample of 16 sales receipts for mail-order sales results in a mean sale amount of $74.50 with a standard deviation of $17.25.

A random sample of 9 sales receipts for internet sales results in a mean sale amount of $84.40 with a standard deviation of $21.25.

The pivotal quantity that will be used for constructing 99% confidence interval for true mean difference 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 for mail-order sales = $74.50

$\bar X_2$ = sample mean for internet sales = $84.40

$s_1$ = sample standard deviation for mail-order purchases = $17.25

$s_2$ = sample standard deviation for internet purchases = $21.25

$n_1$ = sample of sales receipts for mail-order purchases = 16

$n_2$ = sample of sales receipts for internet purchases = 9

Also, $s_p =\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times s_2^{2} }{n_1+n_2-2} }$ = $\sqrt{\frac{(16-1)\times 17.25^{2}+(9-1)\times 21.25^{2} }{16+9-2} }$ = 18.74

The true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is represented by ( $\mu_1-\mu_2$ ).

Now, 99% confidence interval for ( $\mu_1-\mu_2$ ) is given by;

= $(\bar X_1-\bar X_2) \pm t_(_\frac{\alpha}{2}_) \times s_p \times \sqrt{\frac{1}{n_1} +\frac{1}{n_2}}$

Here, the critical value of t at 0.5% level of significance and 23 degrees of freedom is given as 2.807.

= $(74.50-84.40) \pm (2.807 \times 18.74 \times \sqrt{\frac{1}{16} +\frac{1}{9}})$

= [$-31.82 , $12.02]

Hence, 99% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is [$(-31.82) , $12.02].

5 0

2 years ago

A coordinate grid with 2 lines. The first line is labeled y equals negative StartFraction 7 over 4 EndFraction x plus StartFract

LekaFEV [45]

Answer:

Question 1. (2.2, -1.4)

Question 2. (1.33, 1)

Step-by-step explanation:

Equations for the given lines are

-----(1)

It is given that this line passes through two points (0, 2.5) and (2.2, 1.4).

------(2)

This equation passes through (0, -3) and (2.2, -1.4).

Now we have to find a common point through which these lines pass or solution of these equations.

From equations (1) and (2),

x =

x = 2.2

From equation (2),

y = -1.4

Therefore, solution of these equations is (2.2, -1.4).

Question 2.

The given equations are y = 1.5x - 1 and y = 1

From these equations,

1 = 1.5x - 1

1.5x = 2

x =

Therefore, the solution of the system of linear equations is (1.33, 1).

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2 years ago

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Sarah received \$55$55dollar sign, 55 for her birthday. She used some of that money to buy 333 shirts priced at mmm dollars each

satela [25.4K]

Answer:

$(55-3m) is the amount of money she has left

Step-by-step explanation:

In this question, we are asked to give an expression to represent how much money was left after Sarah had bought some certain stuffs at some prices using the money she received at her birthday.

Firstly, we identify that the total amount of money she has to spend is $55.

Now let’s project her total spendings. She bought 3 shirts with each shirt costing $m.

The total amount spent on the shirts is thus; 3 * $m = $3m

The amount of money she has left is the difference.

Mathematically, this is equal to $55 - $3m

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2 years ago

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nasty-shy [4]

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