1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
olga_2 [115]
3 years ago
5

Rag the operation signs to make the equation true. An operation may be used once. More than once, or not at all × returned to ch

oices list. +−×÷ 12 ( 7 − 4 ) + 5 3 = 19
Mathematics
1 answer:
-BARSIC- [3]3 years ago
3 0

Answer:

12/(7-4) + 5 * 3 = 19

Step-by-step explanation:

Given

Untrue Expression: 12 ( 7 − 4 ) + 5 3 = 19

Signs: +−×÷

Required

Use the given signs to make the equation true.

To solve this, the trial and error method will be adopted.

The trial and error method involves trying series of sign combinations in the given expression; whichever works is the right answer.

So, after few attempts the following makes the equation true

12/(7-4) + 5 * 3 = 19

To check if it's true or not; we simply expand the expression on the left hand side. This gives

12/3 + 5 * 3 = 19

4 + 5 * 3 = 19

4 + 15 = 19

19 = 19.

Hence, the sign combinations used in 12/(7-4) + 5 * 3 = 19 is correct.

You might be interested in
The owner of Matt’s Gas Station wants to study gasoline purchases of customers at his station. In 2017, the mean amount of gas
gulaghasi [49]

Answer:

Step-by-step explanation:

a) We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

µ = 9

For the alternative hypothesis,

µ ≠ 9

This is a 2 tailed test

Since the population standard deviation is given, z score would be determined from the normal distribution table. The formula is

z = (x - µ)/(σ/√n)

Where

x = sample mean

µ = population mean

σ = population standard deviation

n = number of samples

From the information given,

µ = 9

x = 9.9

σ = 2.5

n = 50

z = (9.9 - 9)/(2.5/√50) = 2.55

Looking at the normal distribution table, the probability corresponding to the area above the z score is 1 - 0.99461 = 0.00539

Recall, population mean is 9

The difference between sample sample mean and population mean is 9.9 - 9 = 0.9

Since the curve is symmetrical and it is a two tailed test, the x value for the left tail is 9 - 0.9 = 8.1

the x value for the right tail is 9 + 0.9 = 9.9

These means are higher and lower than the null mean. Thus, they are evidence in favour of the alternative hypothesis. We will look at the area in both tails. Since it is showing in one tail only, we would double the area. We already got the area above the z score as z = 0.00539

We would double this area to include the area in the left tail of z = - 2.55. Thus

p = 0.00539 × 2 = 0.01078

Since alpha, 0.01 < 0.01078, we would reject the null hypothesis

But we are told to use the critical value approach, then

Since α = 0.01, the critical value is determined from the normal distribution table.

For the left, α/2 = 0.01/2 = 0.005

The z score for an area to the left of 0.005 is - 2.575

For the right, α/2 = 1 - 0.005 = 0.995

The z score for an area to the right of 0.995 is 2.575

In order to reject the null hypothesis, the test statistic must be smaller than - 2.575 or greater than 2.575

Since - 2.55 > - 2.575 and 2.55 < 2.575, we would reject the null hypothesis. This corresponds to our previous decision.

b) we would assume normal distribution because the sample size is sufficiently large and the population standard deviation is known.

c) Confidence interval is written in the form,

(Sample mean ± margin of error)

Since the sample size is large and the population standard deviation is known, we would use the following formula and determine the z score from the normal distribution table.

Margin of error = z × σ/√n

The z score for confidence level of 99% is 2.58

Margin of error = 2.58 × 2.5/√50 = 0.91

Confidence interval = 9.9 ± 0.91

The lower end of the confidence interval is

9.9 - 0.91 = 8.99

Therefore, p = 9 will be contained in the interval.

4 0
3 years ago
What are the coordinates of the midpoint for segment AB if A is (14 , -2) and B is (7 , -8)
Alenkasestr [34]

Answer:

Step-by-step explanation:

(14 + 7)/2 = 21/2= 10.5

(-2 + (-8))/2= -10/2= -5

Midpoint(10.5, -5)

5 0
3 years ago
Please help me asap ty ty :)
Zanzabum

Answer:

x-intercept = (-9,0)

y-intercept = (0,27)

Step-by-step explanation:

So first we will convert 9x - 3y = -81 into slope intercept form (y=mx+b).

Subtract 9x on both sides to get -3y = -9x -81. Next divide -3 on both sides to get y = 3x + 27.

Since b is the y-intercept, in y=mx+b and 27 is in the position of b, we can already tell that 27 is the y-intercept. So we will write it as (0,27) because coordinates are supposed to be written as (x,y).

Now in order to find the x-intercept, we will have to plug in 0 for y, in the original equation, so we can solve for x.

So we have: 9x -3(0) = -81

Since 3 × 0 = 0, we now have 9x - 0 = -81. So next we add 0 on both sides to get 9x = -81, and then we divide by 9 to get x = -9. So we will write this as (-9,0).

Hope this helps you :)

8 0
2 years ago
How does f(x) = 3 ^x change over the interval x = 4 to x= 5
zloy xaker [14]

Answer:

f(x) = 3^x increases steadily on the interval [4,5].

Step-by-step explanation:

This exponential function f(x) = 3^x has a positive base (3) which is larger than 1.  Thus, this function continues to increase as x increases, including the case where x increases from 4 to 5.

6 0
3 years ago
A team has P points.
stich3 [128]
<span>There were 12 wins. If they played 35 games, 12 were won and 14 were drawn, you just subtract them from 35 and you get 9. The team lost 9 games.</span>
4 0
3 years ago
Other questions:
  • Michelle is building a rectangular landing strip for airplanes .She has material to cover 1/1,500 of a square mile. The landing
    8·1 answer
  • Old joe is 100 years old. If is brother is 5%older than joe, how old is his older brother
    12·1 answer
  • HELP ME PLEASE HURRY...​
    13·2 answers
  • What quadrilaterals are also parallelogram
    10·1 answer
  • Please answer correctly i need help with these.
    10·2 answers
  • F(x)=-2x+4<br> what is x when f(x)=-8
    8·2 answers
  • 2,704 rounded to the nearest thousand
    9·1 answer
  • PLEASE HELP!!! Which is a correct scatter plot for the data set?
    11·1 answer
  • Can y'all help me with my math problem please
    7·2 answers
  • Write an<br> explicit formula for An, the nth term of the sequence 35, 42, 49, ....
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!