All categories

3 years ago

Twice the difference between a number and 4 is twenty. Find the number.

Mathematics

2 answers:

kogti [31]3 years ago

7 0

Answer:

D 14

Step-by-step explanation:

Let x be the number

2(x-4) = 20

Divide each side by 2

2/2(x-4) = 20/2

x-4 = 10

Add 4 to each side

x-4+4 = 10+4

x = 14

Vikki [24]3 years ago

5 0

Answer:

The number is 14

Step-by-step explanation:

Let's call this unknown number of x:

2×(x – 4) = 20

2x – 8 = 20

2x = 20 + 8

2x = 28

x = 28/2

x = 14

You might be interested in

Which of the following is the same as 8.4 × 102 ? A. 84 B. 8,400 C. .84 D. 840

aleksklad [387]

Based on the given answers, do you possibly mean 100 instead of 102?
If so, you would move the decimal point of 8.4 two places to the right, meaning the answer would be letter D. 840.

6 0

3 years ago

Gribbles are small, pale white, marine worms that bore through wood. While sometimes considered a pest since they can wreck wood

Stells [14]

<u>Answer with explanation:</u>

As per given , we have

A sample of 50 gribbles finds an average length of 3.1 mm with a standard deviation of 0.72.

i.e. n= 50

Degree of freedom = n-1=49

$\overline{x}=3.1\ mm$

$s=0.72\ mm$

The point estimate of the population mean is equals to the sample mean.

i.e. The best estimate for the length of gribbles= 3.1 mm

Also, population standard deviation is unknown , then the confidence interval would be :

$E=t_{\alpha/2, df}\dfrac{s}{\sqrt{n}}$

For df= 49 and significance level of 0.05 , the t- value (using t-distribution table) would be :

$t_{0.05/2, 49}=t_{0.025, 49}= 2.010$

Now, Margin of error : $E=(2.010)\dfrac{0.72}{\sqrt{50}}$

$=0.204664986747\approx0.20$

95% confidence interval : $(\overline{x}-E,\ \overline{x}+E)$

$i.e.\ (3.1-0.20, 3.1+0.20)=(2.90,\ 3.30)$

3 0

4 years ago

Which expression is equivalent to 9x + 4x ?

Valentin [98]

13x is that what you meant???

4 0

3 years ago

7 2/3-(-4 1/4)<br> calculate each diffrence.estimate before calculating

Hatshy [7]

Answer:

11 11/12

Step-by-step explanation:

its approximately 12

8 0

4 years ago

A cashier at Giorgio's Grocery Store gets paid $8 per hour for shifts of 6 hours or less and $12 per hour for working shifts ove

cupoosta [38]

Given :

A cashier at Giorgio's Grocery Store gets paid $8 per hour for shifts of 6 hours or less.

And $12 per hour for working shifts over 6 hours long.

To Find :

A function best represents this situation.

Solution :

Let, number of hours is h and amount paid is y .

For, h ≤ 6

y = 8h

For, h > 6

y = 12h

Therefore, function representing this is :

y( h ) = 8h , x ≤ 6

12h , x > 6

Hence, this is the required solution.

5 0

3 years ago