Tutors Answer Your Questions about Radicals (FREE)
Question 1095268: how much xsquare -y square ? if x+y=66 xy=9
Found 4 solutions by KMST, ikleyn, greenestamps, MathTherapy: Answer by KMST(5345) (Show Source):
You can put this solution on YOUR website! ONE WAY:
Maybe we know about solving quadratic equations.
Sometimes we can solve a quadratic equation such as by factoring if we find two integers such that and .
Then those values for and are the solutions of the equation and the equation is really
.
The solutions to a quadratic equation of the form are always two numbers whose sum and product can be found are and respectively.
Unfortunately, sometimes those numbers are irrational, or even imaginary, and then factoring is not an option.
Then, w must use algebra to "complete the square" and then solve, or apply the dreaded quadratic formula
that says the solutions to an equation of the form are given by

To avoid confusion, I used for the variable instead of , and I prefer equations where the leading coefficient is , so I wrote my equation as .
I will make and to get .
The solutions will be the numbers and (or and ) that add up to and whose product is .
The quadratic formula tells me that the solution are given by

The solutions to the equation are and 
One is and the other is , but there is no way to guess which was intended to be and which was intended to be .
and are
and

The possible answers are
and 
ANOTHER APPROACH:
We know that . If we only knew the value of we could easily find the value of
We know that , but to calculate we would need the value of
We know that and we know the values of and 
Substituting the known values we get --> -->
Now we can use that value of to calculate the values of and , and from that find the value of 

Then 
Multiplying times
Answer by ikleyn(53748) (Show Source): Answer by greenestamps(13327) (Show Source): Answer by MathTherapy(10806) (Show Source):
Question 316943: simplify: sqrt (121) / (9)
a) sqrt (11) / sqrt (3)
b) 3 sqrt (11)
c) 11/3
d) sqrt (11) / (3)
Answer by MathTherapy(10806) (Show Source):
Question 1030250: I need help simplifying this expression:

I removed the common factor out of the square root to obtain , but the answer key says it is .
How is it possible? Am I missing out on a rule here?
Found 2 solutions by greenestamps, MathTherapy: Answer by greenestamps(13327) (Show Source): Answer by MathTherapy(10806) (Show Source):
You can put this solution on YOUR website! I need help simplifying this expression:
I removed the common factor out of the square root to obtain , but the answer key says it is .
How is it possible? Am I missing out on a rule here?
*************************************
This happens to be one of those RARE cases when you can actually factor out a COMMON factor, which happens to be a
PERFECT SQUARE (in 4). This is what you did:
=
----- Applying =
....At this point, you haven't fully simplified the
expression, and should've continued as follows:
---- Changing 6 to 5 + 1, and 5 to 5*1
---- Applying =
--- Converting
The above is in the form: , with , and so:
then becomes:
----- Cancelling SQUARE and SQUARE ROOT
=
This certainly matches the answer key:
=====
On the other hand, this author would've SIMPLIFIED the SURD from the onset, as follows:
----- Replacing 8 with factors, 2 & 4
----- Converting 4 to
----- Applying =
---- Changing 24 to 20 + 4, and applying =
---- Converting
The above is in the form: , with , and so:
then becomes:
----- Cancelling SQUARE and SQUARE ROOT
This certainly matches the answer key: 
Question 973976: what is (4- square root of 8) divided by (2+ square root of 8) simplified
Answer by MathTherapy(10806) (Show Source):
Question 78896: please help me simplify this problem?
sqrt /sqrt
Found 3 solutions by ikleyn, timofer, MathTherapy: Answer by ikleyn(53748) (Show Source): Answer by timofer(155) (Show Source): Answer by MathTherapy(10806) (Show Source):
Question 669305: Please help me simplify this: sqrt(x^4y^7)
Answer by MathTherapy(10806) (Show Source):
Question 60849: solve for x by using the quadratic formula: 9x^2-6x+5=0
thanks so much
Answer by ikleyn(53748) (Show Source):
Question 60848: help on this please,,thanks
x+1= sqrt x+7
Answer by ikleyn(53748) (Show Source):
You can put this solution on YOUR website! .
help on this please,, thanks
x+1= sqrt(x+7)
~~~~~~~~~~~~~~~~~~~~~~~~
The solution in the post by @jai_kos is incorrect.
See my correct solution below.
x+1= sqrt(x+7)
Square on both sides, we get
(x+1)^2 = x +7
x^2 + 2x + 1 = x + 7
Reduce it to the standard form quadratic equation
x^2 + x - 6 = 0
Factor left side
(x+3)*(x-2) = 0
The roots of this equation are x = -3 and x = 2.
Direct check shows that x = 2 is the solution to the original equation, while x = -3 is an EXTRANEOUS solution.
ANSWER. The given equation has a unique solution in real numbers x = 2.
Solved correctly.
Question 681800: I'm trying to prove that
Answer by MathTherapy(10806) (Show Source):
Question 1107093: One pair of integers (x.y) solves , find x*y.
Answer by MathTherapy(10806) (Show Source):
Question 1124474: How would you simplify the equation:
Sqrt(17-12sqrt2) in the form
(a+bsqrt2)
Thank you.
Answer by MathTherapy(10806) (Show Source):
Question 263259: solve: x^5/6 + x^2/3-2x^1/2 =0
thanks!
Answer by ikleyn(53748) (Show Source):
Question 1094302: Solving by substitution with u


creates quadratic = 


u = 2,-1
going back and using those two outputs in 
and 
and 
Finally, I get and
But -2 can't be in a radical and would 4 turn into 2,-2 or just 2?
Answer by MathTherapy(10806) (Show Source):
You can put this solution on YOUR website!
Solving by substitution with u
creates quadratic =
u = 2,-1
going back and using those two outputs in
and
and
Finally, I get and
But -2 can't be in a radical and would 4 turn into 2,-2 or just 2?
******************************************************************
u = 2,-1 <=== This is okay!
"going back and using those two outputs in and <=== Here's where I guess
you got confused, and substituted 2 and - 1 for x in
But, u = 2, as you mentioned above, NOT x = 2. And, because you'd substituted u for earlier, at this juncture, you
need to BACK-SUBSTITUTE the value of u to get:
---- Squaring both sides
(x - 4)(x + 1) = 0
x - 4 = 0 OR x + 1 = 0
x = 4 OR x = - 1
Now, you have 2 values for x that you can CHECK to ensure that they're VALID and NOT EXTRANEOUS.
Also, u = - 1, as you mentioned above. And, because you'd substituted u for earlier, at this juncture, you need
to BACK-SUBSTITUTE the value of u to get:
Seeing that the square root of ANY expression is positive (> 0), it's obvious that u = - 1 is an EXTRANEOUS value. As such,
x = 4, or x = - 1 (see above).
Question 569284: solve the following radical:
Answer by MathTherapy(10806) (Show Source):
You can put this solution on YOUR website!
solve the following radical:
**********************************************<
Just like "Rational-functions/875226", - 12 is NOT a solution. It's an
EXTRANEOUS root. Only VALID and ACCEPTABLE answer: 
Question 864099: Can you show me how to Rationalize the denominator and simply the equation
6 / the square root of 2 - the square root of 3.
Answer by MathTherapy(10806) (Show Source):
Question 864097: Can you show me how to Rationalize the denominator and simply the equation the square root of 6 / the square root of 5 - the square root of 3.
Answer by MathTherapy(10806) (Show Source):
Question 707329: How would you solve this equation?
Answer by MathTherapy(10806) (Show Source):
Question 144143: Hello. Please help me solve this problem: I need to find the simplest radical form and the approximate answer of .





x = 0.8944
Answer by MathTherapy(10806) (Show Source):
You can put this solution on YOUR website!
Hello. Please help me solve this problem:
I need to find the simplest radical form and the approximate answer of .
x = 0.8944
*****************
---- Multiplying by LCD, 2x
----- Squaring each side
However, the negative x-value, is EXTRANEOUS, therefore leaving the sole VALID x-value, .
Great job!! You got up to this point: , but needed to go a little further, by RATIONALIZING the
DENOMINATOR, as demonstrated above. Your decimal approximation, x = 0.8944, is also CORRECT.
I don't know why you sought help. You didn't need it!
Again, great job!!
Question 798582: Simplify if necessary. Then rationalize the denominator.
Answer by MathTherapy(10806) (Show Source):
Question 459722: Simplify each expression by rationalizing the denominator.
3/sqrt(7)
2sqrt(2)/sqrt(5)
3sqrt(2)/sqrt(6)
2sqrt(5)/sqrt(12)
Answer by MathTherapy(10806) (Show Source):
Question 904562:
Answer by MathTherapy(10806) (Show Source):
Question 296793: Please help me solve this equation
Answer by MathTherapy(10806) (Show Source):
Question 37745: Hi, I'm having trouble with this problem. Do you think you could help me?
Answer by MathTherapy(10806) (Show Source):
Question 729072: square root of x+7=square root of 2x-3 (+2) not under the square root)
Answer by MathTherapy(10806) (Show Source):
Question 519668: how do you solve the following:
+ =
Answer by MathTherapy(10806) (Show Source):
Question 701399: simplify
Answer by MathTherapy(10806) (Show Source):
Question 993742: Hello. I am having an issue solving this problem and I look to you for help. My problem is:
- + . By using prime factorization, I know that 12 = 2^2*3
50 = 5^2*2
72 = 3^2*2^3
Now, I plug these terms back in and I get:
- + If I continue, I get:
- +
The answer key shows that the answer should be
- Can you see where I went wrong? I'm not coming up with the right answer.
Answer by MathTherapy(10806) (Show Source):
Question 1179144: For what values of c will x² +28x + c = 0 have no real solutions? Explain
Answer by ikleyn(53748) (Show Source):
You can put this solution on YOUR website! .
For what values of c will x^2 +28x + c = 0 have no real solutions? Explain
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The given quadratic equation has no real solutions if and only if its discriminant is a negative value.
The discriminant is d = 28^2 - 4c = 784 - 4c.
The condition of negativity the discriminant is
784 - 4c < 0, or 4c > 784, c > 784/4 = 196.
ANSWER. The given equation has no real solutions at c > 196.
Solved.
Question 787079: Simplify the expression. Assume that all variables are positive
√x/5*√x/20
Answer by MathTherapy(10806) (Show Source):
Question 99475: Perform the indicated division. Rationalize the denominator if necessary. Then simplify each radical expression
-9-sqrt(108) dived by 3
Answer by MathTherapy(10806) (Show Source):
Question 293344: how would you solve this proof?
Answer by MathTherapy(10806) (Show Source):
Question 485164: Write the following expression as a radical and simplify if possible.
(-64)^4/3
Answer by MathTherapy(10806) (Show Source):
Question 732218: how do you do √50x√18?
Found 2 solutions by MathTherapy, ikleyn: Answer by MathTherapy(10806) (Show Source): Answer by ikleyn(53748) (Show Source):
Question 735358: Rationalize 2 divided by 1 minus the square root of 2
Answer by ikleyn(53748) (Show Source):
Question 736159: I am not sure how to work this problem out. (It asks for me to show my work)
x^5*x^√
Answer by ikleyn(53748) (Show Source):
You can put this solution on YOUR website! .
I am not sure how to work this problem out. (It asks for me to show my work)
x^5*x^√
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As the "problem" is written, it does not make sense.
So, this collection of words and mathematical symbols is NOT a Math problem
and, THEREFORE, is NOT a subject for discussion as a Math problem at this forum.
My condolences.
Question 633567: Please help me solve, a=?, b=35, c= 37
Found 3 solutions by mccravyedwin, Edwin McCravy, ikleyn: Answer by mccravyedwin(421) (Show Source):
You can put this solution on YOUR website!
As always, Ikleyn has to be a smarty pants. She constantly criticizes the
struggling students who post on this site. She mainly wants to show how
clever she is, even though the clever method she uses is often not the one
the teacher is teaching.
So now she has to criticize me for criticizing her. Before she wrote this
I was thinking of congratulating her for not criticizing this student for
failing to give the necessary equation.
No, I'm not here to "show my presence". It is important to show the student
that if the question were this,
Given , b=35, c=37, what is a?
then the answer could be a = 12 or a = -12.
Edwin
Answer by Edwin McCravy(20077) (Show Source): Answer by ikleyn(53748) (Show Source):
You can put this solution on YOUR website! .
Please help me solve, a=?, b=35, c= 37
~~~~~~~~~~~~~~~~~~~~~~~~~
I consider it as a Pythagorean equation
a^2 + b^2 = c^2,
a^2 + 35^2 = 37^2,
a^2 = 37^2 - 35^2 = (37-35)*(37+35) = 2*72 = 144,
a^2 = 144,
a = = 12.
--------------------------------
Looking at Edwin's post, I clearly see that Edwin wants to show his presence here,
but I don't see much point in his introducing a negative value for the quantity
representing the length of a segment.
Only so I could refute it.
|
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, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755
|