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

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

Question 84110: Solve using the quadratic formula.
2x2 - 5x � 10 = 0

Click here to see answer by venugopalramana(3286)

Question 84158: The Prime numbers between successive gaps of ten numbers are:
2, 3, 5, and 7.
11, 13, 17, and 19.
23 and 29.
31 and 37.
41, 43, 47, and (not 49 - square of 7)
53 and 59.
61 and 67.
71, 73, and 79 and (not 77)
83 and 89.
91 and 97.
Can you see a pattern forming? Despite of this I was not able to formulate a simple and general expression so that I could tell whether or not a number is prime by simply looking at the number and applying the above sequence. Can you help? Please! I am very excited about this project. It is my own thought and has not been assigned to me as a homework.
Thankyou.
Click here to see answer by rapaljer(4671)

Question 86658: find the GCF by prime factorization
61. 64, 160, and 224
Click here to see answer by checkley75(3666)

Question 86742: I need help with the following problem.
Someone spilled ink on a bill for 36 sweatshirts. If only the first and last digits were covered and the other three digits were, in order, 8, 3, 9 as in
?83.9?, how much did each cost?
I do not have a clue how to do this problem. Please help.
Thank you for your time, it is appreciated.
Sincerely,
R. Franke
Click here to see answer by Edwin McCravy(20054)

Question 86869: I need help with this problem. The problem states:
Two digits of this number were erased: 273*49*5. However we know that 9 and 11 divide the number. What is it?
What I have done so far:
2+7+3+*+4+9+*+5 = 30+*+*
The only number divisible by both 9 and 11 is 99. However, to make the sum of this number equal 99 the two missing digits would have to be 35 and 34. Would these numbers be correct? I have tried other single digit numbers and haven't found a sum divided by both 9 and 11.
Your help would be appreciated. Thanks.
Sincerely
R. Franke
Click here to see answer by ankor@dixie-net.com(22740)

Question 86740: I need help with this problem. The problem states:
Two digits of this number were erased: 273*49*5. However we know that 9 and 11 divide the number. What is it?
What I have done so far:
2+7+3+*+4+9+*+5 = 30+*+*
The only number divisible by both 9 and 11 is 99. However, to make the sum of this number equal 99 the two digits would have to be 35 and 34. I am not sure if these numbers qualify? I tried other single numbers and haven't found a sum divided by both 9 and 11.
Your help would be most appreciated. Thanks.
Sincerely,
R. Franke
Click here to see answer by scott8148(6628)

Question 88232: Hi there,
I have to express my answer in simplest form after adding this problem. The problem reads like this: 6/3x-2 + 3/2x.
I'm not even really sure what to do, so any help you can give me would be greatly appreciated!
Thank you so much!!

Click here to see answer by longjonsilver(2297)

Question 89198: hello, would you please help me on this problem, x^2-x-6/x^2-4=. Thank you.
Click here to see answer by Nate(3500)

Question 90999: Express the decimal number4693 as a binary number.
Click here to see answer by stanbon(75887)

Question 90997: Find two numbers that, if multiplied, would generate a 400-digit number.
Click here to see answer by checkley75(3666)

Question 91315: Can not find what it is, but here goes
dividing rational expression to its lowest terms
7x/4wx * 5x/12w
Click here to see answer by chitra(359)

Question 91457: Find two factors of 15 with a difference of 2.
Click here to see answer by checkley71(8403)

Question 91913: Find the GFC
60. (6y to the power of 2 - 3y)( y + 7)

Click here to see answer by funmath(2933)

Question 92172: Simplify: 4/15 - 3/5 - 5/6
Click here to see answer by anraymer(35)

Question 92969: The following matrix is obtained from a system of equations

The solution to the system is ___________
Click here to see answer by Edwin McCravy(20054)

Question 92959: The following matrix is obtained from a system of equations

The solution to the system is ___________.
Click here to see answer by Edwin McCravy(20054)

Question 93077: a number under 100 and above 1 that has only 5 factors
Click here to see answer by Edwin McCravy(20054)

Question 93626: what is divisible to 3 and 4
Click here to see answer by bucky(2189)

Question 93812: what are the prime factorization of 61?
Click here to see answer by stanbon(75887)

Question 93812: what are the prime factorization of 61?
Click here to see answer by checkley75(3666)

Question 93825: The LCM of 2 consecutive numbers is greater than 200 and is a multiple of seven. Name the numbers.
Click here to see answer by stanbon(75887)

Question 93870: How do you find the answer to this math problem? 3 1/3 divided by ? = -8
Click here to see answer by funmath(2933)

Question 93870: How do you find the answer to this math problem? 3 1/3 divided by ? = -8
Click here to see answer by stanbon(75887)

Question 93870: How do you find the answer to this math problem? 3 1/3 divided by ? = -8
Click here to see answer by checkley75(3666)

Question 95663: When using prime factorization method for finding the least common multiples, why are only certain prime number used instead of all prime numbers? How will I know what prime numbers to use?
6= 2.3
8= 2.2.2=2
LCM=2.2.2.3=24
What tells me to only use three of the four 2s?
Click here to see answer by stanbon(75887)

Question 82079: (4n/3n)+(2/n+1)+(2/n^2+n)...I need that to be completly simplified.
Thanks
Click here to see answer by edjones(8007)

Question 96502: Can you name me all prime numbers under 200!
Thankyou very much
Click here to see answer by jim_thompson5910(35256)

Question 97222: Evaluate the expression.
8(17 - 6.2)
Click here to see answer by miwarto(1)

Question 97567: iam less then 100 iam a multiple of 9 iam a multiple of 6 iam a square number what number fits all these clues
Click here to see answer by checkley71(8403)

Question 97640: WHAT ARE THE FACTORS OF 48
Click here to see answer by checkley71(8403)

Question 97845: Can you take me step by step in helping me with the prime factorization for the numbers 34, 37, 67, 123, and 71? I would love to learn how to do theses so that I may understand when testing time comes around.
Thank you.
Click here to see answer by coyote(32)

Question 97923: Prove that n^3 + (n+1)^3 + (n+2)^3 is divisible by 9 for all n in Natural numbers. I have tried, let mathematical induction, let P(n) be the statement, then then n^9 - n is divisible by 9. I'm stuck...
Thanks
Click here to see answer by aaaaaaaa(138)

Question 98045: Rewrite the numbers as products of their greatest common factor.
14, 10
Click here to see answer by stanbon(75887)

Question 98773: When a positive integer "k" is divided by 6, the remainder is 1. What is the remainder when 5k is divided by 3?
thank you very much
Click here to see answer by scott8148(6628)

Question 98948: can the sum of two prime mubers be a prime number?
Click here to see answer by jim_thompson5910(35256)

Question 100333: What is the least number divisible by four prime numbers?
Click here to see answer by checkley71(8403)

Question 103157: "With the exception of 2 and 3, every prime number is a multiple of 6, add or take away 1. Is this true?"

Click here to see answer by MathLover1(20849)

Question 103551: Ok, I'm stumped. Divide the rational expressions.
x^4-x^3+x^2+x / x^3-4x^2+x-4 (these are the numerators)
2x^3+2x^2+x+1 / 2x^3-8x^2+x-4 (these are the denominators)
Here's what I have.
X(x^3-x^2+x)* 2x^2(x-4)+(x-4) nuerators
2x^2(x+1)(x+1) * x^2 (x-4)(x-4) denominators
now I'm stumped on factoring the first numerator
Click here to see answer by jim_thompson5910(35256)

Question 105219: factor 126 into prime numbers
Click here to see answer by jim_thompson5910(35256)

Question 105669: 2nd question is same as 1st, factor tree. How do I do and what is the prime factorization of the number.
90
5 x _
_ x _ x 2
_ x _ x _ x _
Click here to see answer by elima(1433)

Question 105665: Write the factors for each of the following numbers. 48, 72, 93 and 126.
Click here to see answer by elima(1433)

Question 105805: How do you figure out the prime factorization of a number and what exactly does that mean. These are the numbers I need to find the prime factorization of.
16, 35, 50, 144, 136, 90, 320.
Click here to see answer by stanbon(75887)

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