Questions on Algebra: Divisibility and Prime Numbers answered by real tutors!

Tutors Answer Your Questions about Divisibility and Prime Numbers (FREE)

Question 36211: a) For any prime p>=5, prove that p2+2 ( P square +2) is composite or not.
b) Find the smallest number n, which has the following properties:
1).Its decimal represenation has 4 as the last digit;
2).It is divisible by 3 and 8.
3).Its a square number
Click here to see answer by venugopalramana(3286)

Question 36565: solve:
20 over x = 20 over x-4 + 4 over x
show work
Click here to see answer by stanbon(75887)

Question 36307: a) What is the remainder left after dividing
1! + 2! + 3! +��+ 100! by 7?

b) If n >=4 then find whether 2.n is less than 4.n or not.

Click here to see answer by venugopalramana(3286)

Question 36731: I am trying to help my child complete an extra credit paper from edHelper.com but I cannot find any info on how to work this out. It's like you need to work backward instead of forward to get it, but after several hours, we just can't figure it out! Thanks for any help you can offer.
"Identify two numbers whose GCF is 12 and whose LCM is 396. Describe how you found the number."
Click here to see answer by venugopalramana(3286)

Question 38090: which of the following numbers are composit?
0, 1, 15, 19, 23, 31, 49, 55, 59, 87, 91, 97, 103, 105
Click here to see answer by fractalier(6550)

Question 38153: Find two factors of 28 with a sum of 11
Click here to see answer by checkley71(8403)

Question 38159: What is the greatest common factor for each of the following groups of numbers:
36, 72 and 144
Click here to see answer by checkley71(8403)

Question 38159: What is the greatest common factor for each of the following groups of numbers:
36, 72 and 144
Click here to see answer by AnlytcPhil(1806)

Question 38198: Evaluate the following. Be sure to use the proper units.
5 lb/ft X 3 ft
Click here to see answer by fractalier(6550)

Question 38225: Evette has 41 1/2 ft. of string. She wants to cut it into pieces 3 3/4 ft. long. How many pieces of string will she have? How much string remains, if any?
Thanks!
Click here to see answer by Nate(3500)

Question 38235: write this fraction in simplest form:

42/55 = ?
Click here to see answer by mszlmb(115)

Question 38236: How do you change this fraction to an improper fraction?

13 2/5
Click here to see answer by stanbon(75887)

Question 38241: Divide this problem in simplest form:

3/4 divided by 9
Click here to see answer by lyra(94)

Question 38243: divide this problem in simplest form:
5 1/2 divided by 2 2/5
Click here to see answer by stanbon(75887)

Question 38243: divide this problem in simplest form:
5 1/2 divided by 2 2/5
Click here to see answer by lyra(94)

Question 38254: Divide this problem in simplest form:
5 1/3 divided by 2 2/5
Click here to see answer by lyra(94)

Question 38226: A computer can execute 36 instructions per microsecond. How many instructions can it execute in 4 minutes?
Thanks!
Click here to see answer by lyra(94)

Question 38224: A piece of land measures 3 3/4 acres and is for sale at $60,000. What is the price per acre?
Click here to see answer by lyra(94)

Question 38223: Divide. Write result in simplest form:
3/4 divide by 9

5 1/3 divided by 2 2/5
2 problems to resolve
Thanks
Click here to see answer by fractalier(6550)

Question 38393: Can you list the factors of the number 8?
Click here to see answer by fractalier(6550)

Question 38394: Can 89/13, 151/11 or 223/23 be simplivied?
Click here to see answer by fractalier(6550)

Question 38395: How do you change 3 2/5 to an improper fraction?
Click here to see answer by fractalier(6550)

Question 38396: How do you change 28/9 to a mixed or whole number.
Click here to see answer by fractalier(6550)

Question 38396: How do you change 28/9 to a mixed or whole number.
Click here to see answer by Nate(3500)

Question 38391: What is the product of 126 and 604
Click here to see answer by fractalier(6550)

Question 38404: What is the prime factorization of the number 20
Click here to see answer by fractalier(6550)

Question 38404: What is the prime factorization of the number 20
Click here to see answer by Nate(3500)

Question 38409: List the factors of the number 27.
Click here to see answer by Nate(3500)

Question 38409: List the factors of the number 27.
Click here to see answer by fractalier(6550)

Question 38410: List all the prime numbers between 45 and 80.
Click here to see answer by fractalier(6550)

Question 38407: At lunch, 7 people out of a group of 14 had hamburgers. What fraction names the part of the group who had hamburgers? What fraction names the part who did not have hamburgers?
Click here to see answer by Nate(3500)

Question 38406: How do you write the following in the expanded form?:

684
Click here to see answer by AnlytcPhil(1806)

Question 38511: Can you help me with this:
6 3/4 divided by 3
Click here to see answer by Nate(3500)

Question 38511: Can you help me with this:
6 3/4 divided by 3
Click here to see answer by stanbon(75887)

Question 38526: How do you write the number in expanded form:

30,672
Click here to see answer by Alwayscheerful(414)

Question 38548: Can you write the numbers 684 in expanded form?
Thank you
Click here to see answer by fractalier(6550)

Question 38547:
Can 89/13, 151/11 or 223/23 be simplified? Even though they are reduced to the lowest terms, but can they be simplified? Which ones can or none of the above. Thank you
Click here to see answer by AnlytcPhil(1806)

Question 38552: How do you write up and find the prime factorization of the number 20?
Click here to see answer by checkley71(8403)

Question 38593: Evaluate this problem and answer in the lowest terms:
9/11 - 3/11 + 7/11
Click here to see answer by hellyeah(21)

Question 38592: Add in the lowest terms.
13/18 + 11/18
Click here to see answer by hellyeah(21)

Question 38594:
How do you find the least common multiple (LCM) for the following group of numbers?
12, 20, and 35
Click here to see answer by hellyeah(21)

Question 38595: Can you help me solve the following problem. It has to be answered in the lowest terms.
One task took 7 minutes (min), a second task took 12 minutes, and a third task took 21 min. How long did the three tasks take, as a fraction of an hour?
Click here to see answer by lyra(94)

Question 38597: Can you help me subtract:

13/15 - 11/20
Thanks!
Click here to see answer by rapaljer(4671)

Question 38596: Add:
1/3 + 5/12 + 4/5
Click here to see answer by lyra(94)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295