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 571023: what is value of infinite.
Answer by nyc_function(2626) About Me  (Show Source):
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You can find your answer at the link below.

http://en.wikipedia.org/wiki/Infinity


Question 569377: Please help solve:
There exists x in Q, such that you have 3x^2-27=0. Q= rational numbers

Answer by IWork4Dessert(57) About Me  (Show Source):
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This problem is very fancily worded, but is really very simple. All you need to do is solve the equation.
3x^2-27=0
Move 27 to the other side...
3x^2=27
Divide both sides by 3 to get the variable alone...
x^2=9
Solve for x.
x=3
Hope this helps :)


Question 566671: I need to divide and express the result in standard form:
5+2i/2-5i I know the answer is i just not sure how to get there.

Answer by mananth(10539) About Me  (Show Source):
You can put this solution on YOUR website!
%285%2B2i%29%2F%282-5i+%29

multiply and divide by (2+5i)


%28%285%2B2i%29%282%2B5i%29%29%2F%28%282-5i+%29%282%2B5i%29%29

%2810%2B25i%2B4i%2B10i%5E2%29%2F%284-25i%5E2%29 (i^2=-1)
%2810%2B29i-10%29%2F%2829%29
29i%2F29
=i





Question 566660: Solve the following system of equations by any method you wish.
3x - 5 = y
2y = 6x - 9

Answer by mananth(10539) About Me  (Show Source):
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3 x -1 y = 5 .............1
-6 x + 2 y = -9 .............2
Eliminate y
multiply (1)by 2
Multiply (2) by 1
6 x -2 y = 10
-6 x 2 y = -9
Add the two equations
0 x = 1
This is absurd
there is no solution to this system
The lines are parallel
write the equations in slope intercept formthe slopes are same and the y intercepts are different.


Question 565132: what rational number is between 7/10 and 4/5?
Answer by nyc_function(2626) About Me  (Show Source):
You can put this solution on YOUR website!
To find the fraction that lies between 7/10 and 4/5, add the two given fractions and then divide by 2.

7/10 + 4/5 = 3/2

Now, 3/2 divided by 2 = 3/4

Done!


Question 563701: I am working with subtraction of real numbers. I can not seem to grasp this. All my work on my own has been wrong and I do not understand how to do these.
Answer by richard1234(4789) About Me  (Show Source):
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It's similar to the subtraction you learned in elementary school, e.g. 10-6 = 4. However it's more general since you can allow for negative numbers, fractions/decimals, etc. as in the following examples:

5 - 8 = -3
5 - (-8) = 5+8
-3.8 - (-2) = -3.8 + 2 = -1.8
-104 - 1 = -105
1/2 - 1/4 = 2/4 - 1/4 = 1/4
2/5 - (-3/10) = 2/5 + 3/10 = 4/10 + 3/10 = 7/10
1/3 - 4/9 = 3/9 - 4/9 = -1/9


Question 563621: an avestment is losing value at a rate of 8% per year and now has a value of $8200. find the investment in 5 years
Answer by stanbon(48502) About Me  (Show Source):
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an avestment is losing value at a rate of 8% per year and now has a value of $8200. find the investment in 5 years
-----
Ans = 8200*0.92^5 = $5404.47
===================
Cheers,
Stan H.


Question 563024: 1. What is the difference between natural numbers and rational numbers?
2. What is the difference between rational numbers and real numbers?
3. What is the difference between whole numbers and integers?
4. Why is there a rule that says x^0=1?
5. Why is there a rule that says 5/0 = undefined?

Answer by richard1234(4789) About Me  (Show Source):
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For #1-3, review what natural numbers, rational numbers, integers, etc. are defined as.

For #4, x^0 = 1 because x^(a-b) = (x^a)(x^b), so if a = b, x^0 = (x^a)/(x^a) = 1 (assume x is not 0).

For #5, 5/0 is undefined because we cannot divide 5 into groups of zero.


Question 560033: Solve: 10m − 3 + m < 30
Answer by Maths68(1140) About Me  (Show Source):

Question 559938: -10 + 15 I need help learning how to do this!

Found 2 solutions by bluemockingjay7, fcabanski:
Answer by bluemockingjay7(41) About Me  (Show Source):
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-10 + 15
its like you have a debt of $10 and you paid them $15 dollars....Guess how much you get back...
-10 + 15 = 5
so if you paid them $15 dollars for a $10 debt, you get $5 back as change.

Answer by fcabanski(385) About Me  (Show Source):
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There are simple rules for adding integers.


- If the signs are the same add them and carry the sign.
- If the signs are different subtract the smaller number from the larger, then carry the sign of the larger.


-10 + +15. The signs are different:
15-10 = 5
Carry the sign of the larger (+15), which makes it +5.

If you need help understanding math so you can solve these problems yourself, then one on one online tutoring is the answer ($30/hr). If you need faster solutions with guaranteed detailed answers, then go with personal problem solving ($3.50-$5.50 per problem). Contact me at fcabanski@hotmail.com



Question 558223: How many ways can you get 675 using 123489? Example: 281+394=675
Answer by richard1234(4789) About Me  (Show Source):
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Suppose we use two three-digit numbers.

To get 5 as a units digit, we need either 4+1, 3+2. Since 9+6 = 5 and 8+7 = 5 (mod 10) we cannot use 8 and 9 for the units digit (since we would need a 6 or 7).

Therefore we have either {4,1} or {3,2} as the units digits. Note that the tens digits have to be 8 and 9 since putting them in the hundreds place would create numbers too large. For the hundreds digits, use the set that wasn't used for the units digits (e.g. if 4,1 are units digits, use 3,2). Due to carrying, the hundreds digit will always be 6.

This now becomes a combinatorics problem where we assign digits to each number. We can evaluate the number of ways using combinatorics, but we have to account for overcounting and commutativity (e.g. 281+394 = 394+281), so I'll just list them out:

183 + 492
182 + 493
193 + 482
192 + 483
281 + 394
284 + 391
291 + 384
294 + 381
This leaves 8 ways.

Now, suppose we use a three-digit number, a two-digit number, and a one-digit number. This is obviously impossible, since the largest value we can obtain is 498 + 32 + 1 < 675. Additionally, no other combination of digits (e.g. four-digit plus two-digit) can work, so we have 8 ways.


Question 556970: hello, i am new to this online help. I really do not know where consecutive numbers/integers lie in algebra. i do not know how to work a problem for consecutive numbers. the algebra question i am trying to learn how to solve is this:
the product of two consecutive odd numbers is 399. what are these numbers?

Answer by Alan3354(21542) About Me  (Show Source):
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the product of two consecutive odd numbers is 399. what are these numbers?
-----------
If you factor 399, you find it has a factor of 19.
399 = 19*21
--------------
If you do it the "hard way"
x*(x+2) = 399
x%5E2+%2B+2x+-+399+=+0
Now you have to factor 399 anyway.
--> 19 & 21
---------------
Another way:
sqrt%28399%29 is almost 20, the middle of the 2 numbers.
--> 19 & 21


Question 556353: What is 5/9? Real number, Irrational number.
Answer by jim_thompson5910(21667) About Me  (Show Source):
You can put this solution on YOUR website!
5/9 is real and it's rational, so it's NOT irrational.


Question 556204: How do I change 33 1/3% to a fraction?
Answer by Alan3354(21542) About Me  (Show Source):
You can put this solution on YOUR website!
How do I change 33 1/3% to a fraction?
---------
33 1/3 = 100/3%
-----
(100/3)/100 = 1/3


Question 555928: Is it possible for a negative number to be greater than a positive number?explain
Answer by solver91311(12114) About Me  (Show Source):
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In a word, no. Draw yourself a number line. One number is greater than the other if and only if the greater number is to the right of the other number on the number line. All negative numbers are to the left of zero. All positive numbers are to the right of zero. In order for a negative number to be greater than a positive number, the negative number would have to be somewhere on the right hand side of zero, which is to say that it wouldn't be negative.

John

My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism



Question 554696: Is -0.002 irrational and a integer?
Answer by jim_thompson5910(21667) About Me  (Show Source):
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-0.002 = -2/1000 = -1/500, which makes it a rational number. So it is NOT irrational.


It's also NOT an integer since it has a decimal part (that is nonzero). In other words, it is NOT a whole number (since it's NOT an integer).


Question 554569: What is the difference between rational, irrational, etc.?
Answer by kkasko(45) About Me  (Show Source):
You can put this solution on YOUR website!
What is the difference between rational, irrational, etc.?
Rational and irrational are the exact opposite of each other. A rational number is one that can be wrote as a fraction. Irrational numbers cannot be written as fractions.


Question 554294: How long will my shadow be if im 4 feet 7 inches. For four hours- nine, ten,twelve, and eleven in the morning
Answer by Alan3354(21542) About Me  (Show Source):
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How long will my shadow be if im 4 feet 7 inches. For four hours- nine, ten,twelve, and eleven in the morning
------------
It will vary with the latitude and the date.


Question 553665: How do you distibute 2-(x-7)?
Answer by 10301650(25) About Me  (Show Source):
You can put this solution on YOUR website!
2-(x-7)
(distribute the negative first)
2(-x+7)
(now, distribute the 2)
-2x+14


Question 553688: Solve giving real and complex numbers:
x^3 - 3x^2 + x - 3 = 0

Answer by KMST(576) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E3+-+3x%5E2+%2B+x+-+3+=+0
FACTORING BY GROUPING
%28x%5E3+-+3x%5E2%29+%2B+%28x+-+3%29+=+0 --> x%5E2%28x+-+3%29+%2B+%28x+-+3%29+=+0 --> %28x%5E2%2B1%29%28x+-+3%29
The real solution is the solution to x-3=0 --> x=3
The imaginary solutions are the solutions to
x%5E2%2B1=0 --> x=i and x=-i


Question 553174: Find the distance between ;
J(-9,5) and K(-4,-2)

Answer by stanbon(48502) About Me  (Show Source):
You can put this solution on YOUR website!
the distance between ;
J(-9,5) and K(-4,-2)
-----------------
d = sqrt[(5--2)^2 + (5--4)^2]
---
d = sqrt[49 +81]
----
d = sqrt[130]
====================
Cheers,
Stan H.
======================


Question 553144: Find the distance between each pair of points,Round to the nearest tenth,if necessary. V(-3,-4),W(-1,-2)
Thank you

Answer by jim_thompson5910(21667) About Me  (Show Source):
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Use the distance formula


d = sqrt((x2-x1)^2+(y2-y1)^2)


Remember that the two generic points are (x1, y1) and (x2, y2)
So (x1, y1) = (-3, -4), which means x1=-3 and y1=-4
and (x2, y2) = (-1, -2), which means x2=-1 and y2=-2

So in short, x1=-3, y1=-4, x2=-1, and y2=-2.

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


d = sqrt((x2-x1)^2+(y2-y1)^2)


d = sqrt((-1-(-3))^2+(-2-(-4))^2)


d = sqrt((-1+3)^2+(-2+4)^2)


d = sqrt((2)^2+(2)^2)


d = sqrt(4+4)


d = sqrt(8)


d = 2*sqrt(2)


d = 2.8284271247462



So exact distance between the two points is approximately 2.8 units.


Question 552880: Is -3/1 Rational, if so is it a natural number,intenger, or a whole number?
Or is it irrational?

Answer by jim_thompson5910(21667) About Me  (Show Source):
You can put this solution on YOUR website!
-3/1 is rational (since it's a fraction of two integers) and it's an integer (since -3/1 = -3)


Question 552629: In a sequence, what is the difference in this one? -4.5,-12.5,-62.5
Answer by AnlytcPhil(1116) About Me  (Show Source):
You can put this solution on YOUR website!
There is no common difference, because that is not an arithmetic sequence.
It's also not a geometric sequence, because there is no common ratio.

However the nth term has this formula:

an = -21nē+55n-38.5 

And the sequence taken to a few more terms is:

-4.5,-12.5,-62.5, -154.5, -288.5, -464.5, ...


Edwin


Question 552195: Name the set or sets of numbers to which sqrt 48 belongs.
Answer by jim_thompson5910(21667) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt(48) is both a real number and an irrational number (since you cannot represent it as a fraction of integers).


Question 552009: what type of number is closed under subtraction?
prime numbers

Answer by solver91311(12114) About Me  (Show Source):
You can put this solution on YOUR website!


If the primes are closed under subtraction, then the result of any prime subtracted from any prime will have a prime result. Is 7 minus 3 a prime number?

John

My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism



Question 551595: 1/2 + (2/3 divided by 3/4) - (4/5 times 5/6) = 13/18
I can't get how to work this problem out to get this answer!!!

Answer by Alan3354(21542) About Me  (Show Source):
You can put this solution on YOUR website!
1/2 + (2/3 divided by 3/4) - (4/5 times 5/6)
= 1/2 + (2/3 * 4/3) - (4/5 times 5/6) Invert the divisor and multiply
= 1/2 + 8/9 - 20/30
= 1/2 + 8/9 - 2/3
Find a common denominator. 54 works
= 27/54 + 48/54 - 36/54
= 39/54
= 13/18


Question 551421: Is -12 a real, rational or irrational number?
Answer by KMST(576) About Me  (Show Source):
You can put this solution on YOUR website!
Real numbers are all the numbers that we use for real measurements. (That's not an official definition, but may help you understand what "real number" means).
Real numbers include all integers, like, 2, 0, and -12.
Real numbers include all RATIOnal numbers that can be expressed as RATIOs of two integers, like 3/4, -5/7, 2, 0, and -12. (Some of those rational numbers are integers; the others are what you used to call fractions).
Real numbers also include numbers that are not rational, but are real anyway, like pi, and sqrt%282%29. We know pi is real because it's the length of the circumference of a circle with a diameter measuring 1%2F3. We know sqrt%282%29 is real because it's the length of the diagonal of a square with sides measuring 1. We cannot express pi or sqrt%282%29 as fractions (rational numbers), or a decimal number that end or repeat, like 7%2F25=0.28, or 1%2F12=0.0833333.... . The best we can do with irrational numbers is write approximations like 3.14, or 3.142, or 3.1416, or 3.14159 for pi, but there is no rhyme or reason to what the next digit will be.
The number -12 is definitely real. Sometimes that's been the temperature outside; it was really cold. It is also a rational number, and it is also an integer. It is not an irrational number.


Question 551051: The driving distance between Pensacola and Key West is 792 miles. Bus A leaves Pensacola at 6:00 a.m. traveling at an average 42 miles per hour. Bus B leaves Key West at 7:00 a.m. traveling at an average speed of 33 miles per hour. At what distance, in miles, from Key West will the two buses meet?
This question has me confused so please help me with this.

Found 2 solutions by mananth, oberobic:
Answer by mananth(10539) About Me  (Show Source):
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Pensacola at 6:00 a.m. traveling at an average 42 miles per hour. Bus B leaves Key West at 7:00 a.m. traveling at an average speed of 33 miles per hour. At what distance, in miles, from Key West will the two buses meet?
This question has me confused so please help me with this.
Bus I = 42 mph
Bus II = 33mph
Bus I has left 1 hour early
Bus I has traveled 42 miles before Bus II starts
The buses are travelling in opposite directions
so their combined speed = 75 mph
Balance distance = 792-42=750 miles
t=d/r
d=750
r=75
t=750/75
t=10 hours after Bus II starts at 7.00 am
From key west Bus II has traveled 33* 10 =330 miles
From Pensacola Bus I has traveled 11*42= 462 miles ( it left 1 hour early)
m.ananth@hotmail.ca

Answer by oberobic(2302) About Me  (Show Source):
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The buses are converging at their combined speed: 42+33 = 75 miles/hr.
When they meet, they will have covered the entire distance: 792 miles.
The fundamental distance equation is: d = r*t
We know 'd' and 'r', so we can solve for 't'.
t = 792 miles / 75 miles/hr = 10.56 hr.
.56 hr * 60 min/hr = 33.6 min.
.
We now have to arrange these facts to answer the question: How far from Key West will they be?
.
Well, the bus that left Key West was going 42 mph * 10.56 hr = 443.52 miles.
.
We can check the distance based on leaving Pensacola.
That bus traveled 33 mph * 10.56 hr = 348.48.
That is how far from Pensacola they are. We know the distance from Pensacola to Key West is 792,
so the bus is 792 - 348.48 = 443.52.
That's confirms the answer since it matches the other distance.
.
Answer: The buses are 443.52 miles from Key West when they meet.
.
Done.


Question 550816: wat is 8-6 5/4?
Answer by JBarnum(1826) About Me  (Show Source):

Question 550497: What is an irrational number?
Answer by stanbon(48502) About Me  (Show Source):
You can put this solution on YOUR website!
What is an irrational number?
----
Irrational means "cannot be expressed as a ratio of integers".
Example:
sqrt(2) cannot be expressed as a ratio of integers.
---------------------
Cheers,
Stan H.
=====================


Question 549508: (1)2 + (.1)2+ (.01)2+...=?
Answer by mathie123(175) About Me  (Show Source):
You can put this solution on YOUR website!
2.22222... (repeated 2 forever)
(As you are adding the smaller decimal place each time )


Question 549567: How do I solve & put in set builder notations? -14 + -7(4-x) < 3(2x -15)
Answer by mathie123(175) About Me  (Show Source):
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-14+%2B+-7%284-x%29+%3C+3%282x+-15%29
Expanding throughout the brackets we get:
-14+-28%2B7x+%3C+6x+-45
Now collecting like terms:
-42%2B7x+%3C+6x+-45
Now getting all values with an x on one side and all constants on the other:
-42%2B7x%2B42-6x+%3C+6x+-45%2B42-6x
7x-6x+%3C-45%2B42
And finally collecting like terms:
x+%3C-3


Question 549172: what is a good definition of irrational and rational numbers

Answer by KMST(576) About Me  (Show Source):
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DISCLAIMER - PERSONAL BELIEF, not official definition:
To me, a rational number is one that is equivalent to the ratio of two integers.
An irrational number is a number that is not rational, but we need to say it's real because it is a needed boundary between sets, or sequences of rational numbers. For example, we can calculate infinity of rational numbers, x, such that x%5E2%3C2, and infinity or rational numbers, y such that y%5E2%3E2. We can find pairs (x,y) as close together as we want. There has to be a number at the boundary between the x's and the y's, but we cannot find a rational number that fits the bill. So we say that the number exists, it's real, but it is not rational. We call it irrational, and we represent it as sqrt%282%29. For other irrational numbers, we cannot even find an analogy so that we can write them as an operation, like square root, on a rational number, and we have to invent a name like pi or e.


Question 549148: How do I solve 5m divided by 4 equals 66? I missed class on Friday and was having trouble with this problem today. Thanks for your help. Damian M.
Answer by oberobic(2302) About Me  (Show Source):
You can put this solution on YOUR website!
+%285%2Am%29%2F4+=+66+
.
Any whole number = itself divided by 1.
.
+%285%2Am%29%2F4+=+66%2F1+
.
cross multiply
.
+%285%2Am%29%2A1+=+66%2A4+
.
+5%2Am+=+264+
.
divide both sides by 5
.
+m+=+264%2F5+=+52.8+
.
Done.


Question 548943: name the rational numbers from this list:
-12,0,1.88,square root 8,square root 25,5 1/4,-19 over -18, 1.1717717771.....

Answer by solver91311(12114) About Me  (Show Source):
You can put this solution on YOUR website!


Rational numbers are those numbers that can be expressed as a ratio of two integers.

John

My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism



Question 548971: solve: -5-(2-5p)
Answer by mananth(10539) About Me  (Show Source):
You can put this solution on YOUR website!
-5-(2-5p)
-5-2+5p
-7p+5p


Question 548947: solve for u
b=hnu

Found 2 solutions by mathie123, mananth:
Answer by mathie123(175) About Me  (Show Source):
Answer by mananth(10539) About Me  (Show Source):
You can put this solution on YOUR website!
b=hnu, solve for u
divide by hn
b/hn=u


Question 547818: Find irrational number between 0.53 and 0.54
Answer by jim_thompson5910(21667) About Me  (Show Source):
You can put this solution on YOUR website!
One such irrational number is sqrt%280.53%2A0.54%29=sqrt%280.2862%29=0.53497663500381


Question 547571: y+6/y-9
Answer by unlockmath(1118) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
We need to know what you want with this,
otherwise we can't help you.
RJ


Question 547116: please help,
-number of real solutions-
1.) -3x^2+9x-8=0
2.)8x^2-11x=-3
3.)x^2=-7x+7
4.)-4x^2-4=8x
i have a test in ALG2 today please quick response thank you

Answer by JBarnum(1826) About Me  (Show Source):
You can put this solution on YOUR website!
1)-3x%5E2%2B9x-8=0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case -3x%5E2%2B9x%2B-8+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%289%29%5E2-4%2A-3%2A-8=-15.

The discriminant -15 is less than zero. That means that there are no solutions among real numbers.

If you are a student of advanced school algebra and are aware about imaginary numbers, read on.


In the field of imaginary numbers, the square root of -15 is + or - sqrt%28+15%29+=+3.87298334620742.

The solution is x%5B12%5D+=+%28-9%2B-+i%2Asqrt%28+-15+%29%29%2F2%5C-3+=++%28-9%2B-+i%2A3.87298334620742%29%2F2%5C-3+

Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-3%2Ax%5E2%2B9%2Ax%2B-8+%29
no real number answers
2)8x%5E2-11x%2B3=0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 8x%5E2%2B-11x%2B3+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-11%29%5E2-4%2A8%2A3=25.

Discriminant d=25 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--11%2B-sqrt%28+25+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-11%29%2Bsqrt%28+25+%29%29%2F2%5C8+=+1
x%5B2%5D+=+%28-%28-11%29-sqrt%28+25+%29%29%2F2%5C8+=+0.375

Quadratic expression 8x%5E2%2B-11x%2B3 can be factored:
8x%5E2%2B-11x%2B3+=+8%28x-1%29%2A%28x-0.375%29
Again, the answer is: 1, 0.375. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+8%2Ax%5E2%2B-11%2Ax%2B3+%29
2 answers
3)x%5E2%2B7x-7=0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B7x%2B-7+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%287%29%5E2-4%2A1%2A-7=77.

Discriminant d=77 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-7%2B-sqrt%28+77+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%287%29%2Bsqrt%28+77+%29%29%2F2%5C1+=+0.887482193696061
x%5B2%5D+=+%28-%287%29-sqrt%28+77+%29%29%2F2%5C1+=+-7.88748219369606

Quadratic expression 1x%5E2%2B7x%2B-7 can be factored:
1x%5E2%2B7x%2B-7+=+1%28x-0.887482193696061%29%2A%28x--7.88748219369606%29
Again, the answer is: 0.887482193696061, -7.88748219369606. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B7%2Ax%2B-7+%29
2 answers
4)-4x%5E2-8x-4=0
-4%28x%5E2%2B2x%2B1%29=0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B2x%2B1+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%282%29%5E2-4%2A1%2A1=0.

Discriminant d=0 is zero! That means that there is only one solution: x+=+%28-%282%29%29%2F2%5C1.
Expression can be factored: 1x%5E2%2B2x%2B1+=+1%28x--1%29%2A%28x--1%29

Again, the answer is: -1, -1. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B2%2Ax%2B1+%29
2 answers


Question 545922: x^(2)-13x+42=0
Answer by JBarnum(1826) About Me  (Show Source):
You can put this solution on YOUR website!
lucky numbers -7 and -6
find two numbers that multiply to get +42 and add to get -13
%28x-7%29%28x-6%29=0
x=7x=6


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