Questions on Algebra: Real numbers, Irrational numbers, etc answered by real tutors!

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Tutors Answer Your Questions about real-numbers (FREE)


Question 751315: What two numbers add to be -16 but when multiplied equal 192?
Answer by stanbon(57361) About Me  (Show Source):
You can put this solution on YOUR website!
What two numbers add to be -16 but when multiplied equal 192?
----
Equations:
x + y = -16
xy = 192
--------------
Rearrange:
x = -16-y
----
(-16-y)y = 192
-16y - y^2 = 192
y^2 + 16y + 192 = 0
-----
No Real Number solution.
Please check your posting for accuracy.
Cheers,
Stan H.


Question 750523: 2√3+6√3-4√3
Answer by stanbon(57361) About Me  (Show Source):
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2√3+6√3-4√3
------
= (2+6-4)sqrt(3)
------
= 4sqrt(3)
=============
Cheers,
Stan H.


Question 750394: if the sum of two consecutive integers is -15< what is the value of the larger integer?
Answer by tommyt3rd(601) About Me  (Show Source):
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(n)+(n+1)=-15

2n+1=-15
2n=-16
n=-8
but -7 is greater (larger)

:)


Question 750392: can a negative number be considered a real number ?
Answer by tommyt3rd(601) About Me  (Show Source):
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Yes - any number that can be graphed on the number line is a real number :)


Question 750353: X%5E2+%2A+X%5E3 divided by X%5E4
Answer by JoeTaxpayer(135) About Me  (Show Source):
You can put this solution on YOUR website!
When multiplying two numbers whose base is the same, we just add the exponents.
X%5EA%2AX%5EB=X%5E%28A%2BB%29
So, x%5E2%2Ax%5E3=x%5E5
And similarly, dividing is to subtract the exponent.
So x%5E5%2Fx%5E4=x
Over time, this will become intuitive, and you'll know the answer is X just by glancing at the problem. Of course, you may need to show steps to keep a teacher happy, but in longer problems, likely, not.


Question 750283: using -1 as a factor, what is x^2 + 2x + 1/-1 - x in simplified form?
Answer by josgarithmetic(1530) About Me  (Show Source):
You can put this solution on YOUR website!
What you mean is this: %28x%5E2+%2B+2x+%2B+1%29%2F%28-1+-+x%29 in simplified form.

Factor.
%28x%2B1%29%28x%2B1%29%2F%28%28-1%29%281%2Bx%29%29
%28x%2B1%29%28x%2B1%29%2F%28%28-1%29%28x%2B1%29%29
cross%28%28x%2B1%29%29%28x%2B1%29%2F%28%28-1%29cross%28%28x%2B1%29%29%29
which only slightly unfinished.


Question 698304: What is the real number solution for x^4-16=0?
Answer by tommyt3rd(601) About Me  (Show Source):

Question 730526: if a=sqrt3-sqrt2%2Fsqrt3%2Bsqrt2+%26+b=sqrt3%2Bsqrt2%2Fsqrt3-sqrt2
"find the value of a^+b^=5ab"

Answer by tommyt3rd(601) About Me  (Show Source):
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what is the value of b?


Question 732990: The highest temperature ever recorded in a desert was 105 degrees F. the coldest temperature recorded in a deert was 5 degrees Fahrenheit below zero. State which real numbers correstpind on the situation.
The real number that corresponds to the highest temp. in a desert is ?
The real number that corresponds to the coldest temp. in a desert is ?

Answer by tommyt3rd(601) About Me  (Show Source):

Question 749636: how many real number solutions? 4x^2+8x-4=0
Answer by tommyt3rd(601) About Me  (Show Source):
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two:
sqrt%28+8%5E2-4%2A4%2A%28-4%29+%29=8sqrt%282%29
so there are 2 irrational solutions

:)


Question 702939: write each rational number as a ratio in the form a/b 1) -3 ??
Answer by tommyt3rd(601) About Me  (Show Source):

Question 747469: For any positive integer 'n' prove that 'n3-n' is divisible by 6.

Answer by tommyt3rd(601) About Me  (Show Source):
You can put this solution on YOUR website!
not true:
n=1
n^3-n=0
Maybe you mean if n is 2 or greater?
%0D%0A%0D%0An%5E3-n=%28n%29%28n%5E2-1%29=%28n-1%29%28n%29%28n%2B1%29%0D%0A

now for
n%3E=2
this product will include 3 consecutive numbers and that means at least one of them will be even and exactly one will be a multiple of 3. Therefore each will be a multiple of 6.


:)


Question 708644: what is the smallest set of real numbers which 12 belongs to
Answer by tommyt3rd(601) About Me  (Show Source):

Question 708371: (7*5)+[5/(4/4)]
Answer by tommyt3rd(601) About Me  (Show Source):
You can put this solution on YOUR website!
(7*5)+[5/(4/4)]=35+5=40


Question 713755: 7+3(9-4)2 / 5 +
Answer by tommyt3rd(601) About Me  (Show Source):
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please repost the question seems to be incomplete :)


Question 749614: Divide (-1)^9
Answer by Alan3354(30993) About Me  (Show Source):
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Divide (-1)^9
divide what?


Question 749598: Find two expression for the number with negative signs in different places. -5/6. - 8/7. 19/-3
Answer by stanbon(57361) About Me  (Show Source):
You can put this solution on YOUR website!
Find two expression for the number with negative signs in different places.
-5/6 = -(5/6)
---------------------
- 8/7 = (-8/7)
---------------------
19/-3 = -19/3
===================
Cheers,
Stan H.
===================


Question 748340: Solve the equation, if possible. Write irrational numbers in simplest radical form. Describe the strategy you used to get your solution and tell why you chose that strategy.
x^2-6x+1=0

Answer by stanbon(57361) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the equation, if possible. Write irrational numbers in simplest radical form. Describe the strategy you used to get your solution and tell why you chose that strategy.
x^2-6x+1=0
----
x = [6 +- sqrt(36-4*1*1)]/2
----
x = [6 +- sqrt(32)]/2
---
x = {6 +- 4sqrt(2)]/2
---
x = [3 +- 2sqrt(2)]
========================
Cheers,
Stan H.
=======================


Question 747631: -5/8+(-1/6)
Found 2 solutions by Alan3354, obulee:
Answer by Alan3354(30993) About Me  (Show Source):
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-5/8+(-1/6)
= -(5/8) - (1/6)
= -30/48 - 8/48
= -38/48
= -19/24

Answer by obulee(5) About Me  (Show Source):
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note dat
+ - = -
-5/8 - 1/6
find the lcm of 8 and 6
- 30-8/48
-22/48
-11/24


Question 747381: what is the discriminant of x^2 + 15x - 1 = 0

Answer by Alan3354(30993) About Me  (Show Source):
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what is the discriminant of x^2 + 15x - 1 = 0
-----------
Disc+=+b%5E2+-+4ac


Question 747101: what is the number of real solutions in -x^2+9x+7=0
Answer by tommyt3rd(601) About Me  (Show Source):
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We can use the discriminant to determine the number and type of solutions:


%0D%0A+sqrt%28+9%5E2-4%2A%28-1%29%2A7+%29=sqrt%28109%29%0D%0A


since the discriminant is real and not 0 we know that there are 2 real solutions

:)


Question 738228: Show that there are infinitely many positive primes.
Answer by tommyt3rd(601) About Me  (Show Source):
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Suppose that there are only n-prime numbers and denote the product of all of the primes as A. Next let B be the product of all of the primes plus 1. Now 1 is not a prime number by definition so for any particular prime p>1. By the fundamental theorem of algebra, our p had to be a divisor of A as well as a divisor of B. Furthermore it also must divide their difference, B-A - which is 1. Since the difference is 1, p must be a divisor of 1 and this is impossible.
Our contradiction tells us that our first statement must be false. There are infinitely many primes.



Question 725020: The number 18 can be written as the sum of 9 consecutive integers.What's the product of these integers?
Answer by tommyt3rd(601) About Me  (Show Source):
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18=sum%28%28x%2Bi%29+%2Ci=0%2C8%29
which when solved leads to x=-2
so our product is
%28-2%29%28-1%29%280%29%281%29%282%29%283%29%284%29%285%29%286%29=0


Question 741951: - 144/4 to which set does the number belong
Answer by tommyt3rd(601) About Me  (Show Source):
You can put this solution on YOUR website!
this number is a fraction so it belongs to the rational numbers - this also means it belongs to the sets of numbers for which the rational numbers are a subset


Question 745363: square root 9u-13=square root7u-8
Answer by nyke@rediffmail.com(5) About Me  (Show Source):
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you mean
+sqrt%289u-13%29+=+sqrt%287u-8%29+
squaring both sides
=> 9u-13 = 7u-8
=> 9u - 7u = -8 + 13
=> 2u = 5
=> u = 5/2
=> u = 2.5


Question 744576: Find the remainder when %281%5E2013+%2B+2%5E2013+%2B+3%5E2013+%2B+...2012%5E2013%29 is divided by 2013 .

Answer by lynnlo(4164) About Me  (Show Source):

Question 744288: Twenty times the square of a non-zero number is equal to 20 time the number. What is the number?
Answer by josgarithmetic(1530) About Me  (Show Source):
You can put this solution on YOUR website!
n is some nonzero number.

20%2An%5E2=20%2An is exactly what you wrote in words. n=1.


Question 743587: 4(x-5)+2=x+3
Answer by jim_thompson5910(28595) About Me  (Show Source):
You can put this solution on YOUR website!
4%28x-5%29%2B2=x%2B3 Start with the given equation.


4x-20%2B2=x%2B3 Distribute.


4x-18=x%2B3 Combine like terms on the left side.


4x=x%2B3%2B18 Add 18 to both sides.


4x-x=3%2B18 Subtract x from both sides.


3x=3%2B18 Combine like terms on the left side.


3x=21 Combine like terms on the right side.


x=%2821%29%2F%283%29 Divide both sides by 3 to isolate x.


x=7 Reduce.


----------------------------------------------------------------------

Answer:

So the solution is x=7


Question 740828: I am trying to indicate what kind of number -144/4 is.
Found 2 solutions by stanbon, solver91311:
Answer by stanbon(57361) About Me  (Show Source):
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I am trying to indicate what kind of number -144/4 is.
----
It's Rational.
----
= -38
-----
It is an Integer
====================
Cheers,
Stan H.
====================

Answer by solver91311(16897) About Me  (Show Source):
You can put this solution on YOUR website!


Hint: is the ratio of two integers. What kind of numbers has the word ratio as part of the name?

John

Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism



Question 739933: Is 2-square root 5 rational or irrational number?
Answer by KMST(1868) About Me  (Show Source):
You can put this solution on YOUR website!
2-sqrt%285%29 is irrational because sqrt%285%29 is irrational.
You know that the result from adding, or subtracting, or multiplying rational numbers is always rational.
If a is rational, 2-a must be rational.
If 2-sqrt%285%29 was rational,
2-%282-sqrt%285%29%29=2-2%2Bsqrt%285%29=sqrt%285%29 would be rational,
but it is not.

NOTE:
Watch out for trick questions.
Sometimes rational numbers are written in an unusual way to make them look irrational, just to trick you.
sqrt%284%29=2 is a rational number, even when it is written as sqrt%284%29
Similarly, sqrt%289%2F4%29=3%2F2 is rational, and so is


Question 740089: is -144/4 a real number? I know it can reduce to -36, so that is what is confusing me...
Answer by MathLover1(6634) About Me  (Show Source):
You can put this solution on YOUR website!

Real Numbers include:
Whole Numbers (like 1,2,3,4, etc)
Rational Numbers (like 3/4, 0.125, 0.333..., 1.1, etc )
Irrational Numbers (like pi,sqrt(3), etc )
Real Numbers can also be positive, negative or zero.
so, your answer is: -144%2F4=-36 is a real number


Question 739950: INSERT TWO RATIONAL NUMBERS BETWEEN 2 AND 3
Answer by KMST(1868) About Me  (Show Source):
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There is an infinite number of choices. Just pick a denominator (or 2), make up fractions that are less than 1, and add those fractions to 2.
For example,
2%261%2F3=7%2F3 and 2%262%2F3=8%2F3 are between 2 and 3
2%3C2%261%2F3=7%2F3%3C2%262%2F3=8%2F3%3C3

2%262%2F5=12%2F5 and 2%263%2F5=13%2F5 would work too
and so would 2%5E3%2F1000=2003%2F1000 and 2%26537%2F1000=2537%2F1000 ,
or any combination.
There are many fractions of 1=3-2 that we can add to 2 and still end up with less than 3.

If asked for 5 rational numbers between 2 and 3, you could use
2%261%2F100=201%2F100, 2%262%2F100=202%2F100=101%2F50, 2%263%2F100=203%2F100, 2%264%2F100=204%2F100=51%2F25, and 2%265%2F100=205%2F100=41%2F20


Question 739947: insert a rational number between 2 and 3
Answer by KMST(1868) About Me  (Show Source):
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One of the infinity of choices is:
2%261%2F2=5%2F2
2%3C2%261%2F2=5%2F2%3C3


Question 738382: X^2-25x=0
Answer by checkley79(3050) About Me  (Show Source):
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X^2-25x=0
(X+5)(X-5)=0
X+5=0
X=-5 ANS.
X-5=0
X=5 ANS.


Question 738376: 10c^2 + 25c – 6c – 15 factor by grouping
Answer by jim_thompson5910(28595) About Me  (Show Source):
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10c%5E2%2B25c-6c-15 Start with the given expression


%2810c%5E2%2B25c%29%2B%28-6c-15%29 Group the terms in two pairs


5c%282c%2B5%29-3%282c%2B5%29 Factor out the GCF 5c out of the first group. Factor out the GCF -3 out of the second group


%285c-3%29%282c%2B5%29 Since we have the common term 2c%2B5, we can combine like terms


So 10c%5E2%2B25c-6c-15 factors to %285c-3%29%282c%2B5%29


In other words, 10c%5E2%2B25c-6c-15=%285c-3%29%282c%2B5%29


Question 738342: (x-2)(x+2)/3x-6 simplify
Answer by jim_thompson5910(28595) About Me  (Show Source):
You can put this solution on YOUR website!
%28%28x-2%29%28x%2B2%29%29%2F%283x-6%29

%28%28x-2%29%28x%2B2%29%29%2F%283%28x-2%29%29

%28highlight%28%28x-2%29%29%28x%2B2%29%29%2F%283%2Ahighlight%28%28x-2%29%29%29

%28cross%28%28x-2%29%29%28x%2B2%29%29%2F%283%2Across%28%28x-2%29%29%29

%28x%2B2%29%2F3

Final Answer: %28x%2B2%29%2F3


Question 738243: what is the fraction of 16.62?
Answer by ankor@dixie-net.com(15656) About Me  (Show Source):
You can put this solution on YOUR website!
what is the fraction of 16.62?
just like you say it: 16 and 62%2F100
Both numerator and denominator are even, reduce by dividing both by 2
16 31%2F50
31 is prime so you're done


Question 738231: If a & b are two odd prime numbers, show that a^2-b^2 is composite.
Answer by MathLover1(6634) About Me  (Show Source):
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Assume p > q. Since p, q are both odd, p - q ≥ 2. Also, q ≥ 3, p ≥ 5.
Since p² - q² = (p + q) (p - q) where p + q, where p + q > p ≥ 5, and p - q ≥ 2, p² - q² is composite.


Question 737749: Evaluate ((100001^2)-(99999^2))/100000.
Answer by MathLover1(6634) About Me  (Show Source):

Question 736715: Solve:
If (-6/n) is not a rational number, what MUST the value of n be?

Answer by stanbon(57361) About Me  (Show Source):
You can put this solution on YOUR website!
Solve:
If (-6/n) is not a rational number, what MUST the value of n be?
------
n must be an irrational number.
============
Cheers,
Stan H.


Question 734572: Solve for x
2x-1/7=3(1-2x)/2
I got the answer x=23/46
is this right? can you show me your working for this so i can compare it to mine?

Answer by MathLover1(6634) About Me  (Show Source):
You can put this solution on YOUR website!

%282x-1%29%2F7=3%281-2x%29%2F2

%282x-1%29%2F7=%283-6x%29%2F2.....cross multiply

2%282x-1%29=7%283-6x%29

4x-2=21-42x

4x%2B42x=21%2B2

46x=23

x=23%2F46.....so, your answer is correct!!!!!




Question 733816: X2+5x-2
Answer by jim_thompson5910(28595) About Me  (Show Source):
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What do you want to do here? Graph it? If so, then the graph is below



Question 731893: Perform the indicated operation (2x^3+x^2-x+1) / (2x+3) (use long division)
Answer by lynnlo(4164) About Me  (Show Source):
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x^2-x+1-2/2x+3


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