Questions on Algebra: Negative and Fractional exponents answered by real tutors!

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Tutors Answer Your Questions about Exponents-negative-and-fractional (FREE)


Question 750612: Hello, I am trying to solve a algebra math problem but not sure what the next step to take is. Please help me understand and help solve this problem, thank you.
Question: Simplify. Not to use negative exponents in answer.
(3m^ -5n)^4
___________ * (-4mn^3)^2
(9m^2n^ -2)
For this problem I start off by making the negative exponents positive by placing 1 to go over the ones that have negative exponents.
1
__
3m^5 and but after I get the negative exponents to be positive, I am not sure what the next step is and what to do with (-4mn^3)^2

Answer by Edwin McCravy(8909) About Me  (Show Source):
You can put this solution on YOUR website!
See how you like this way where we get rid of parentheses first.
I'm going to take more steps than necessary because you can do 
several of these steps all in one step:

expr%28%283m%5E%28-5%29n%29%5E4%2F%289m%5E2n%5E%28-2%29%29+%29%2A%284mn%5E3%29%5E2

1. We make sure every factor shows its 1 exponent if it doesn't already 
have another exponent.  Like this:



2. When you have a fraction multiplied by a non-fraction, make the
non-fraction into a fraction by putting a 1 under it:



3. Next remove the parentheses by distributing every exponent
that is inside the parentheses times the exponent just outside the
parentheses. The -4 will be squared so we can just ignore the negative
dign: 



4. There are only two negative exponents. The rule is: Move the
factors with negative exponents on the bottom to the top, and on
the top to the bottom, and change the sign of the exponent to
positive.  So we move m-20 to the bottom as m20 and we move n-2 to the top as n2.



5. Let's just have one big fraction:

+%283%5E4n%5E2n%5E4%2A4%5E2m%5E2n%5E6%29%2F%289%5E1m%5E2m%5E20%29+   

6. Let's add the exponents of like letters in order to multiply:

+%283%5E4n%5E12%2A4%5E2m%5E2%29%2F%289%5E1m%5E22%29+

7. Let's subtract the exponents larger minus smaller
and place the result where the larger exponent was
The m22 is on the bottom and the m2 is on the
top. So we subtract exponents 22-2 and get 20 and write m20 on
the bottom because the larger exponent was on the bottom.

+%283%5E4n%5E12%2A4%5E2%29%2F%289%5E1m%5E20%29+

8.  Write the 91 as 9 and then as 32

+%283%5E4n%5E12%2A4%5E2%29%2F%283%5E2m%5E20%29+

9. Subtract the exponents of 3 and get 32 on the top
because the largere exponent was on top. 

+%283%5E2n%5E12%2A4%5E2%29%2F%28m%5E20%29+

10. Write 32 as 9 and  42 as 16

+%289n%5E12%2A16%29%2F%28m%5E20%29+ 

11. Multiply the 9 by the 16 and get 144

+%28144n%5E12%29%2F%28m%5E20%29+

Edwin


Question 749956: Please help!
1/3y ^-3

Answer by unlockmath(1603) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
Math people don't like negative exponents, so to get rid of such place it in the Denominator as:
1/3/(y^3)
This can be rewritten as:
1/(3y^2)
(Note: I'm assuming the original problem was 1/3 times y^-3)
RJ


Question 749470: What is the simplest form of the given expression?
2.9X10^7 / 5.8X10^10

Answer by josgarithmetic(1540) About Me  (Show Source):
You can put this solution on YOUR website!
Your result should fit the form, U.Tx10^p, where U is the digit in the ones place, T is the digit in the tenths place, and p is the exponent, an integer. The "x" is used only as a multiplication symbol.

2.9X10^7 / 5.8X10^10
You mean
%282.9x10%5E7%29%2F%285.8x10%5E10%29
=%282.9%2F5.8%29x10%5E%287-10%29
=0.5x10%5E%28-3%29=5.0x10%5E%28-1%29x10%5E%28-3%29=highlight%285.0x10%5E%28-4%29%29

The system is not rendering everything properly. The highlighted number should show 5.0 x 10^(-4), because we should keep two significant figures for the available accuracy, according to the accuracy available for the starting numbers.


Question 716654: (a^3/m)^-4
Answer by kekegeter (57) About Me  (Show Source):
You can put this solution on YOUR website!
(a^3/m)^-4
a^12/1/m^4
m^4/a^12


Question 722547: (5y^4)^-3(2y^-2)3
Answer by kekegeter (57) About Me  (Show Source):
You can put this solution on YOUR website!
(5y^4)^-3(2y^-2)3
5^-3(y^4)^-3(2y^2)3
5^-3*y^12(2y^2)3
1/5^3*y^12(2y^2)3
6y^2/5^3*y^12
6/125y^10


Question 738140: 1.) 3x+12=15/x
2.) 3/x-3=5/x^2-9-2/x+3

Answer by kekegeter (57) About Me  (Show Source):
You can put this solution on YOUR website!
1) 3x+12=15/x
x є {1, -5}
2) 3/x-3=5/x^2-9-2/x+3
x є {√85-5/6, √85+5/6}


Question 745593: 2/3-4/5-(-11/15)+7/10-5/2
Answer by kekegeter (57) About Me  (Show Source):
You can put this solution on YOUR website!
-36/3*5*2
-6/5 or -1.2


Question 745595: -9.6+7.4-(-3.9)-(-11)
Answer by kekegeter (57) About Me  (Show Source):
You can put this solution on YOUR website!
-9.6 + 7.4 + 3.9 + 11
= 127/10 or 12.7




Question 746098: please help me with this question, and i dont know if this problem is under the correct category sorry. "simplify each expression below. your answer should contain no parentheses and no negative exponents" 5t^-3 (five t negative cube)
Answer by josmiceli(9697) About Me  (Show Source):
You can put this solution on YOUR website!
You are in the right place
+5t%5E%28-3%29+
Use the fact that +t%5E%28-3%29+=+1%2Ft%5E3+
+5t%5E%28-3%29+=+5%2Ft%5E3+


Question 745994: the lowest point in Aftica is lake Assal, which is 512ft below sea level. The lowest point in South Africa is the valdes Peninsula, which is 131 ft below sea level. how much lower is Lake Assal than Valdes Peninsula?
Answer by checkley79(3050) About Me  (Show Source):
You can put this solution on YOUR website!
512-131=381 feet ans.


Question 745588: -4/5-(-4/5)

Answer by tommyt3rd(608) About Me  (Show Source):
You can put this solution on YOUR website!
any number subtracted from itself is 0
:)


Question 745565: We let T = the total change in the level of the lake. Then the problem translate to a sum. T= -5/8 + (-1/6)
Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
T= -5/8 + (-1/6)
---
T = [6*-5 + 8*-1]/(8*6)
----
T = -38/48
-----
T = -19/24
================
Cheers,
Stan H.
===============


Question 745461: Please help me solve this equation:
a^-11 / a^-8
That is: a to the power of negative 11 divide by a to the power of negative 8.
Thank you.

Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
a^-11 / a^-8 = a^8/a^11 = 1/a^3
===================================
Cheers,
Stan H.


Question 745273: I don't understand how to solve:
10x^3 +y^2÷2 -x^3÷3 +y^2÷4 -2x^2÷3
I would really appreciate if you could show me the steps to solving this equation by tonight.
The given answer that was provided to me was 30÷3x^3 -x^3÷3
Thank you.

Answer by rothauserc(210) About Me  (Show Source):
You can put this solution on YOUR website!
we are asked to solve
10x^3 +y^2÷2 -x^3÷3 +y^2÷4 -2x^2÷3
group like terms together and we have
10x^3 - X^3/3 -2x^2/3 +y^2/2 + y^2/4
30x^3/3 - x^3/3 -2x^2/3 +2y^2/4 + y^2/4
29x^3/3 - 2x^2/3 +3y^2/4




Question 743762: 1-2ab-(a²+b²)
Answer by Ed Parker(21) About Me  (Show Source):
You can put this solution on YOUR website!
1 - 2ab - (a² + b²)

Remove the parentheses:

1 - 2ab - a² - b²

Enclose the last three terms in a parentheses preceded by a minus:

1 - (2ab + a² + b²)

Swap the first two terms inside the parentheses:

1 - (a² + 2ab + b²)

Factor the trinomial in the parentheses:

1 - (a + b)(a + b)

Write that as a square:

1 - (a + b)²

Factor as the difference of two squares:

1² - (a + b)²

[1 - (a + b)][1 + (a + b)]

Remove the inner parentheses:

[1 - a - b][1 + a + b]

Change the brackets to parentheses:

(1 - a - b)(1 + a + b)

Edwin


Question 740051: factor 12s^3-21s^2+12s
Answer by MathLover1(6638) About Me  (Show Source):
You can put this solution on YOUR website!

12s%5E3-21s%5E2%2B12s

3s%284s%5E2-7s%2B4%29...since 4s%5E2-7s%2B4 cannot be factored, your final answer is
3s%284s%5E2-7s%2B4%29


Question 739690: 18x^3y^2/30x^4y^5 simplify
Answer by checkley79(3050) About Me  (Show Source):
You can put this solution on YOUR website!
18x^3y^2/30x^4y^5
3/5xy^3 ans.


Question 739691: simplify 12x/3x+9
Answer by checkley79(3050) About Me  (Show Source):
You can put this solution on YOUR website!
12x/3x+9
12x/3(x+3) divide by 3.
4x/(x+3) ans.


Question 739694: simplify 15a+9ab/6a
Answer by checkley79(3050) About Me  (Show Source):
You can put this solution on YOUR website!
15a+9ab/6a
15a+3b/2
3(5a+b/2) ans.


Question 739696: 8m%2F6m%2Bmn simplify
Answer by josgarithmetic(1540) About Me  (Show Source):
You can put this solution on YOUR website!
8m%2F6m%2Bmn
=%288%2F6%29%28m%2Fm%29%2Bmn
=%28%282%2A4%29%2F%282%2A3%29%29%2A1%2Bmn
=%284%2F3%29%2A%282%2F2%29%2A1%2Bmn
=%284%2F3%29%2A1%2A1%2Bmn
=1%261%2F3%2Bmn or %284%2F3%29%2Bmn


Question 739693: simplify 3x^2+6x/3x^2+9x
Answer by josh's girl(6) About Me  (Show Source):
You can put this solution on YOUR website!
Simplifying
3x2 + 6x
Reorder the terms:
6x + 3x2


Simplifying
3x2 + 9x
Reorder the terms:
9x + 3x2


Question 738449: Write answer in scientific notation:
(4.1*10^2)(3*10^-5)
I did: (4.1*3)*(10^2*10^5)=(4.1*3)*10^7=12.3x10^7 as my answer
Here is where I am confused, since the number is greater than 10 should it still be written in scientific notation? Is my answer correct? Thanks
I then reworked the problem as 0.0123 or 1.23x10^-2, a previous answerer said the exp was ^2, which is correct?

Answer by Hchu243(2) About Me  (Show Source):
You can put this solution on YOUR website!
You're first answer was correct, except because your answer was greater than 10, it should be written as 1.23*10^8. You move the decimal point over one and increase the decimal one; in scientific notation, you can only have 1 integer before the decimal.


Question 738395: Write answer in scientific notation:
(4.1*10^2)(3*10^-5)
I did: (4.1*3)*(10^2*10^5)=(4.1*3)*10^7=12.3x10^7 as my answer
Here is where I am confused, since the number is greater than 10 should it still be written in scientific notation? Is my answer correct? Thanks

Answer by checkley79(3050) About Me  (Show Source):
You can put this solution on YOUR website!
YOU CHANGED THE ^-5 TO ^5
(4.1*10^2)(3*10^-5)
410*.00003=0.0123 OR 1.23*10^2 ANS.


Question 738378: A-(9b-13b)=
A=12, b=-2

Found 2 solutions by rfer, jim_thompson5910:
Answer by rfer(12670) About Me  (Show Source):
You can put this solution on YOUR website!
12-(9*-2-13*-2)
12-(-18+26)
12-(8)
12-8=4

Answer by jim_thompson5910(28598) About Me  (Show Source):
You can put this solution on YOUR website!
Replace A with 12 and b with -2, then evaluate like this

A-(9b-13b)

12-(9*(-2)-13*(-2))

12-(-18+26)

12-(8)

12-8

4

So A-(9b-13b) = 4 when A = 12 and b = -2


Question 737996: (2/3)^4
I have to write it in simplest form, so I simplified it to- 2^4/3^4, but do I need to simplify it so it doesn't have the exponents in it anymore?

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

Question 737694: 1.) 3x+12=15/x
2.) 3/x-3=5/x^2-9-2/x+3

Answer by josgarithmetic(1540) About Me  (Show Source):
You can put this solution on YOUR website!
1.) 3x+12=15/x

Clear the fractions. Multiply left and right sides by x. You now have a quadratic equation, easier to solve. Just a little rearranging is needed first.
3x%5E2%2B12x=15
divide b.s. by 3
x%5E2%2B4x=5
x%5E2%2B4x-5=0 and you can finish this one, but check answers against the original equation in case one answer is "extraneous".

2.) 3/x-3=5/x^2-9-2/x+3

That is likely expressed incorrectly so what you want is not clear. If it IS written correctly, then the lowest or simplest denominator is x^2, and you would multiply the left side and right side by x^2 which would clear the fractions.
%283%2Fx-3%29%2Ax%5E2=%285%2Fx%5E2-9-2%2Fx%2B3%29%2Ax%5E2
3x-3x%5E2=5-9x%5E2-2x%2B3x%5E2
3x-3x%5E2%2B9x%5E2-3x%5E2%2B2x-5=0
3x%5E2%2B3x%2B2x%2B5=0
3x%5E2%2B5x%2B5=0
Which use of quadratic formula will give x=%28-5%2B-+sqrt%2825-4%2A3%2A5%29%29%2F15
and that will simplify into x=-%281%2F3%29-%281%2F15%29i%2Asqrt%2835%29 or x=-%281%2F3%29%2B%281%2F15%29i%2Asqrt%2835%29. Complex solutions.


Question 737304: (7x – 0.6) – (-2x2 + 4x – 8)
Answer by rfer(12670) About Me  (Show Source):
You can put this solution on YOUR website!
7x-0.6+2x^2-4x+8=
2x^2+3x+7.4


Question 737308: Use special product formula: (7a + 2)2
Answer by MathLover1(6638) About Me  (Show Source):

Question 737306: (12x^2 - 6x + 3)/3
Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
(12x^2 - 6x + 3)/3
-----
= 4x^2 - 2x + 1
-------
Cheers,
Stan H.


Question 737305: (-4p2 – 3p – 2) + (-p2 – 4)

Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
(-4p2 – 3p – 2) + (-p2 – 4)
------
= -5p^2 -3p -6
========================
Cheers,
Stan H.


Question 734322: How to begin in a problem like this, 4x+3/15 - 2x-3/9 = 6x+4/6 - x . Thank you for any help!
Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
How to begin in a problem like this,
----------------------
4x+3/15 - 2x-3/9 = 6x+4/6 - x
Multiply thru by 90 to get:
-----
6*(4x+3) - 10(2x-3) = 15(6x+4) - 90x
-----
24x + 18 -20x + 30 = 90x + 60 - 90x
-----
4x + 48 = 60
4x = 12
x = 3
================
Cheers,
Stan H.
================


Question 734313: 1 1/6 + x/8 = 7/24 Not sure what to do once I turn the mixed fraction to an improper one. any help would be appreciated. thanks.
Answer by rfer(12670) About Me  (Show Source):
You can put this solution on YOUR website!
7/6+x/8=7/24
x/8=7/24-7/6
x/8=7/24-28/24
x/8=-21/24
x=-21/24*8
x=-7


Question 734233: x^-2 multiplied by x^-3
Answer by MathLover1(6638) About Me  (Show Source):

Question 732491: evaluete 25^3/2
Answer by lynnlo(4164) About Me  (Show Source):

Question 731208: What is 4 divided c times c to the negative fifth power..
Answer by MathLover1(6638) About Me  (Show Source):
You can put this solution on YOUR website!

4 divided c is 4%2Fc
+c to the negative fifth power is c%5E%28-5%29=1%2Fc%5E5
so, 4%2Fc times 1%2Fc%5E5 is %284%2Fc%29%281%2Fc%5E5%29=4%2A1%2F%28c%2Ac%5E5%29=4%2Fc%5E6


Question 730794: what is equal to (6^-7)^3?
A. (1/6)^21
B. (-1/6)^-21
C. (1/6)^-21
D. (-1/6)^21

Answer by lynnlo(4164) About Me  (Show Source):
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YOUR ANSWER IS D.


Question 729748: there are 2. got them wrong on a test and cant come up with the teachers answer
1) solve for X: a/bx-c=0 . I get x=cb/a
2) subtract: 3x+1/x2(squared)-9 minus 2x-2/x2(squared -9. my answer x-1/x2(squared -9

Found 2 solutions by MathLover1, Alan3354:
Answer by MathLover1(6638) About Me  (Show Source):
You can put this solution on YOUR website!

1) solve for X:
a%2Fbx-c=0
a%2Fbx=c
a=cbx
a%2Fcb=x........answer


2) %283x%2B1%29%2F%28x%5E2-9%29+-+%282x-2%29%2F%28x%5E2+-9%29...if denominator same, just subtract numerators
%28%283x%2B1%29+-+%282x-2%29%29%2F%28x%5E2+-9%29

%283x%2B1-2x%2B2%29%2F%28x%5E2+-9%29

%28x%2B3%29%2F%28x%5E2+-3%5E2%29.....factor denominator

%28x%2B3%29%2F%28%28x+-3%29%28x%2B3%29%29

cross%28%28x%2B3%29%291%2F%28%28x+-3%29cross%28%28x%2B3%29%29%29

1%2F%28x+-3%29


Answer by Alan3354(30993) About Me  (Show Source):
You can put this solution on YOUR website!
1) solve for X: a/bx-c=0 . I get x=cb/a
Is it (a/b)x ?
Or a/(bx) ?
2) subtract: 3x+1/x2(squared)-9 minus 2x-2/x2(squared -9. my answer x-1/x2(squared -9
Use ^ (Shift ^) for exponents.


Question 727745: Please help me solve this equation: a^2 over b^2 divided by a over b^3
Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
a^2 over b^2 divided by a over b^3
-----
(a^2/b^2) / (a/b^3)
---
Invert the denominator and multiply:
= (a^2/b^2) * (b^3/a)
-----
= (a^2/a)(b^3/b^2)
Cancel where you can:
----
= ab
===========
Cheers,
Stan H.


Question 726524: 3(x-3)=3
7
3 over 7

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

Question 725301: Simplify: (3x + 4y) - (2x - 5y)
Answer by checkley79(3050) About Me  (Show Source):
You can put this solution on YOUR website!
(3x + 4y) - (2x - 5y)
3X-2X+4Y+5Y
X+9Y ANS.


Question 725217: 5\2x-3-1\x plus 5
Answer by stanbon(57387) About Me  (Show Source):
You can put this solution on YOUR website!
Post using parentheses.
Cheers,
Stan H.


Question 724815: How do I solve this problem? I'm trying to help my daughter and I'm lost.
2a to the -5 power over b to the -6 power.
She is trying to simplify this problem.

Found 2 solutions by mananth, KMST:
Answer by mananth(12270) About Me  (Show Source):
Answer by KMST(1874) About Me  (Show Source):
You can put this solution on YOUR website!
I would not call it simplifying, but we can transform it into an expression with positive exponents:
2a%5E%28-5%29%2Fb%5E%28-6%29=2b%5E6%2Fa%5E5
Any powers with negative exponents can cross the fraction line to make their exponents turn positive.

EXPLANATION:
a%5E%28-5%29=1%2Fa%5E5 by definition, and b%5E%28-6%29=1%2Fb%5E6 too
b%5E%28-6%29=1%2Fb%5E6 <---> b%5E%28-6%29%2Ab%5E6=1 <---> b%5E6=1%2Fb%5E%28-6%29
In baby steps that are not usually spelled out:


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