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.
Assumption:
<em>Something is missing in question. If we see deeply it is apparent that there is some issue with option b i.e. </em><em>B) 8 − 4x 10 = 4 + 2x </em><em>we assume that the questioner want to type </em><em>B) 8-4x^10 = 4 + 2x.</em>
Answer:
The correct answer is <em> </em><em>B) 8-4x^10 = 4 + 2x.</em>
Step-by-step explanation:
All equations given is the question can be solve easily to determine the value of x. However if we solve equation mentioned in option b we cannot get single answer easily.
For example value of x in eq given in option A
15x + 123 = 5x+4
1oX = -119
X = -119/10
The probability of multiple events happening is found by multiplying the probabilities of each event together.
So yes, 1/10 is the answer :)
40x+8x^2=0 can be solved for x (there are two solutions):
Divide all 3 terms by the greatest common multiple (which is 8x):
40x+8x^2=0
------------- -----
8x 8x
5 + x = 0 produces the root x = - 5.
Setting 8x = 0 and solving for x produces the root x = 0.
Be certain to check these results. substitute x = -5 into 40x+8x^2=0. Is the resulting equation true or false? Next, subs. x=-5 into 40x+8x^2=0. Is the resulting equation true or false?