All categories

2 years ago

9. Determine whether or not the number 257 is prime.

Mathematics

1 answer:

Sladkaya [172]2 years ago

7 0

Answer:

257 is prime.

Step-by-step explanation:

To evaluate if a number is prime, we just need to evaluate it for the prime numbers that are equal or lesser than the said number's square root.

In this case, √257 = 16.03 so we just need to see if 257 is divisible by <u>2, 3, 5, 7, 11 and 13</u> (the prime numbers that come before 16)

257 is odd, so it is not divisible by 2.

The sum of its digits is 14, therefore, it is not divisible by 3.

257 ends in 7, therefore it's not divisible by 5.

257/ 7 = 36.71 so it's not divisible by 7.

257/ 11 = 23.36 so it's not divisible by 11

Finally 257 / 13= 19.76 so it's not divisible by 13.

Therefore, 257 is prime.

You might be interested in

What is the midpoint of the line segment graphed below?

FinnZ [79.3K]

Answer:

(3.5, -4.5) or option D

Step-by-step explanation:

x) (6 + 1) / 2 = 3.5

y) (-1 + (-8)) / 2 = -4.5

3 0

2 years ago

Which line is a graph of the equation: 2x + 5y = -10?

Lady bird [3.3K]

Answer:

Step-by-step explanation:

2x + 5y = - 10 Subtract 2x from both sides

5y = -2x - 10 Divide by 5

y = -2x/5 - 10/5

y = 0.4x - 2

The slope is minus so the line is going from lower right to upper left as B and D are doing.

The y intercept is - 2. B goes through + 2 so it is not the answer.

The answer is D

3 0

2 years ago

A bag had 7 orange rocks , 6 green rock , 1 white rock ,7 black rocks , and 2 yellow you randomly pull a rock from the bag ,keep

daser333 [38]

Answer:

$Probability = \frac{7}{253}$

Step-by-step explanation:

Given

$Orange = 7$

$Green = 6$

$White = 1$

$Black = 7$

$Yellow = 2$

Required

Probability of selecting a yellow then orange rock

From the question, we understand that the probability is that of without replacement.

Since the yellow, is first picked.

We need to determine the probability of picking a yellow rock, first.

$P(Yellow) = \frac{n(Yellow)}{Total}$

$P(Yellow) = \frac{2}{7 + 6 + 1 + 7 + 2}$

$P(Yellow) = \frac{2}{23}$

The rock has reduced by 1;

Next is to determine the probability of picking an orange rock

$P(Orange) = \frac{n(Orange)}{Total - 1}$

$P(Orange) = \frac{7}{7 + 6 + 1 + 7 + 2- 1}$

$P(Orange) = \frac{7}{22}$

The required probability is calculated as thus:

$Probability = P(Yellow) * P(Orange)$

$Probability = \frac{2}{23} * \frac{7}{22}$

$Probability = \frac{14}{506}$

$Probability = \frac{7}{253}$

4 0

2 years ago

help plzzz , ik it’s a test n all but this was from last year n I have to do it for this year n it’s due today :( I’ve been stre

Westkost [7]

Answer:

Step-by-step explanation:

2(x)+4=16

2(6)+4=16

12+4=16

7 0

2 years ago

Write the polynomial as a product of linear factors<br> I put a picture <br> Please help!!!!

OLEGan [10]

Factor 2x^4 - 7x^3 -27x^2 + 63x + 81
Write as a Set of Linear Factors
Over the complex numbers
(X+3) (x-3) (x+1) (2x-9)

3 0

3 years ago