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edjones answered: 7568 problems
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Linear-equations/114692: Hi, I previously asked a question here #114329. And what I am asking is for this question I got the first one for the number 2 correct at
2=$74 in unit price. On the remaining ones of 7,9,and 11, I have this: 7=143/2. 9=141/2 and then 11=139/2. I feel that somewhere I messed up or did not do the remaining ones correct. I would greatly appreciate your help.
Thank You,
Barb Neely
1 solutions

Answer 83465 by edjones(7569) About Me  on 2007-12-05 00:54:43 (Show Source):
You can put this solution on YOUR website!
You did mess up.
p=-x/2+75
.
-2/2+75=$74.
.
-7/2+75=$71.5
.
-9/2+75=$70.5
.
-11/2+75=$69.5
.
Ed


Linear-equations/114329: When x number of units are sold, the price of each unit(in dollars) is given by
p=-x/2+75. Find the Unit price when the following quantities are sold: 2,7,9,11.
What I have done is this: p=-2/2+75 p=-1+75 p=$74
My question is for this first number of 2 am I correct?
Thank you for your help and your time,
Barb Neely
1 solutions

Answer 83464 by edjones(7569) About Me  on 2007-12-05 00:52:35 (Show Source):
You can put this solution on YOUR website!
p=-x/2+75
.
-2/2+75=$74.
.
-7/2+75=$71.5
.
-9/2+75=$70.5
.
-11/2+75=$69.5
.
Ed


Polynomials-and-rational-expressions/114545: How do you factor this polynomial x^2-7x=12/x^2-x-6
1 solutions

Answer 83463 by edjones(7569) About Me  on 2007-12-05 00:40:42 (Show Source):
You can put this solution on YOUR website!
x^2-7x+12/x^2-x-6 I think this must be the problem.
(x-3)(x-4)/(x-3)(x+2)
=(x-4)/(x+2)
Ed


Quadratic_Equations/114667: 7x(3x+4)=8(2x+5)+13
1 solutions

Answer 83461 by edjones(7569) About Me  on 2007-12-05 00:28:10 (Show Source):
You can put this solution on YOUR website!
7x(3x+4)=8(2x+5)+13
21x^2+28x=16x+40+13
21x^2+12x-53=0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 21x%5E2%2B12x%2B-53+=+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=%2812%29%5E2-4%2A21%2A-53=4596.

Discriminant d=4596 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-12%2B-sqrt%28+4596+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%2812%29%2Bsqrt%28+4596+%29%29%2F2%5C21+=+1.32842392920746
x%5B2%5D+=+%28-%2812%29-sqrt%28+4596+%29%29%2F2%5C21+=+-1.89985250063603

Quadratic expression 21x%5E2%2B12x%2B-53 can be factored:
21x%5E2%2B12x%2B-53+=+%28x-1.32842392920746%29%2A%28x--1.89985250063603%29
Again, the answer is: 1.32842392920746, -1.89985250063603. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+21%2Ax%5E2%2B12%2Ax%2B-53+%29



Exponents/114558: What is -3(2x^3y^-1)^-3
1 solutions

Answer 83459 by edjones(7569) About Me  on 2007-12-05 00:19:42 (Show Source):
You can put this solution on YOUR website!
-3(2x^3y^-1)^-3
=-3((1/8)x^-9y^3)
=(-3/8)x^-9*y^3
=-3y%5E3%2F8x%5E9
Ed


Expressions-with-variables/114561: Translate " a nember increased by the difference between eleven and the number" into a variable expression and simply.
1 solutions

Answer 83457 by edjones(7569) About Me  on 2007-12-05 00:02:54 (Show Source):
You can put this solution on YOUR website!
x+(11-x)
=x+11-x
=11
Ed


logarithm/114690: How to solve for x in the equation
log(sub 5)(x+4) + log(sub 5)(x) = 2
1 solutions

Answer 83455 by edjones(7569) About Me  on 2007-12-04 23:56:31 (Show Source):
You can put this solution on YOUR website!
log(5)(x+4)+log(5)x=2
log(5)(x(x+4))=2
log(5)(x^2+4x)=2
x^2+4x=5^2
x^2+4x-25=0
x=3.38516... Quadratic formula (see below)
Ed
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B4x%2B-25+=+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=%284%29%5E2-4%2A1%2A-25=116.

Discriminant d=116 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-4%2B-sqrt%28+116+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%284%29%2Bsqrt%28+116+%29%29%2F2%5C1+=+3.3851648071345
x%5B2%5D+=+%28-%284%29-sqrt%28+116+%29%29%2F2%5C1+=+-7.3851648071345

Quadratic expression 1x%5E2%2B4x%2B-25 can be factored:
1x%5E2%2B4x%2B-25+=+%28x-3.3851648071345%29%2A%28x--7.3851648071345%29
Again, the answer is: 3.3851648071345, -7.3851648071345. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B4%2Ax%2B-25+%29



Miscellaneous_Word_Problems/114580: This question is from textbook Algebra Structure and Method
m1=? d1=5
m2=60 d2=9


If anyone can help me with this problem I would appreciate it!!!
Please and Thank You!!!
1 solutions

Answer 83454 by edjones(7569) About Me  on 2007-12-04 23:43:41 (Show Source):
You can put this solution on YOUR website!
m1/m2=d1/d2 I'm guessing this is what they're driving at.
x/60=5/9
60x/60=60*5/9
x=300/9
x=100/3
Ed


Linear-systems/114688: Find the domain of the given function.
h(x)= 1/x+1



____ (Use interval notation.)
1 solutions

Answer 83452 by edjones(7569) About Me  on 2007-12-04 23:35:10 (Show Source):
You can put this solution on YOUR website!
X(-infinity,-1)U(-1,infinity)


Equations/114643: Hi All, I just wanted to thank everyone for your help you have given me these last few weeks. I really appreciate it you have also taught me how to do alot of things that my books could not explain to me, but you all explained things great!! Thanks again, good luck!!
Debbie
1 solutions

Answer 83451 by edjones(7569) About Me  on 2007-12-04 23:32:05 (Show Source):
You can put this solution on YOUR website!
Keep up the good work Debbie.
We'll be here if you ever need us again.


Exponents/114653: This question is from textbook bEGINNING ALGEBRA
I a having a hard time understanding how to do ths problem
48x^5y^3
________
15a^4b^2
1 solutions

Answer 83450 by edjones(7569) About Me  on 2007-12-04 23:28:16 (Show Source):
You can put this solution on YOUR website!
%2848x%5E5y%5E3%29%2F%2815a%5E4b%5E2%29
=%2816x%5E5y%5E3%29%2F%285a%5E4b%5E2%29
That is all you can do with this problem.
Ed


Functions/114664: OH WHAT WOULD YOU PLUG IN FOR X IN THIS PROBLEM
G(X) = X2ND POWER - 2Y
3[G(X)+4]
1 solutions

Answer 83449 by edjones(7569) About Me  on 2007-12-04 23:22:47 (Show Source):
You can put this solution on YOUR website!
Tips:
Big print is hard to read.
x2nd power is x^2. You can find ^ by pressing the shift and 6 key at the same time.
g(x)=x^2-2y
3(g(x)+4)
=3(x^2-2y+4)
=3x^2-6y+12
Ed


Equations/114671: A bicyclist rode into the county for 5 hours. In returning her speed was 5mi/h faster and her trip took 4 hours. What was her speed each way?
1 solutions

Answer 83448 by edjones(7569) About Me  on 2007-12-04 23:13:52 (Show Source):
You can put this solution on YOUR website!
d=st d=dist., s=speed, t=time
st=st
Let s=speed going out. s+5=speed returning
5s=4(s+5)
5s=4s+20
5s-4s=4s-4s+20
s=20 mi/h, s+5=25 mi/h
Check:
20*5=25*4 true
Ed


Proportions/114684: Paul invested $5000 in a time deposit. What interest will he earn for 1 year if the interest rate is 6.5%?
1 solutions

Answer 83446 by edjones(7569) About Me  on 2007-12-04 23:02:11 (Show Source):
You can put this solution on YOUR website!
5000*.065=$325.


Quadratic_Equations/114677: John owns a hotdog stand. He has found that his profit is represented by the equation P%28x%29=+-x%5E2%2B56x%2B73,, where x is the number of hotdogs. How many hotdogs must he sell to make a profit?
P(x)=x^2+56x+73
Choices:
45 hotdogs
28 hotdogs
56 hotdogs
73 hotdogs
Thank you.
1 solutions

Answer 83445 by edjones(7569) About Me  on 2007-12-04 22:58:14 (Show Source):
You can put this solution on YOUR website!
The question is not phrased properly.
One formula has -x^2 in it and the repeat of it has x^2.
The question should be "how many hot dogs must he sell to maximize his profit".
P%28x%29=+-x%5E2%2B56x%2B73
x=-1.27456, x=57.27456 quadratic formula (see below)
(-1.27456+57.27456)/2=28 maximum of the graph
By checking the next graph you can see that he can make a profit by selling between 1 and 57 hot dogs and he makes a maximum profit at 28 hot dogs.
graph%28500%2C500%2C-10%2C75%2C-50%2C1000%2C-x%5E2%2B56x%2B73%29
Ed
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case -1x%5E2%2B56x%2B73+=+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=%2856%29%5E2-4%2A-1%2A73=3428.

Discriminant d=3428 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-56%2B-sqrt%28+3428+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%2856%29%2Bsqrt%28+3428+%29%29%2F2%5C-1+=+-1.27456233660889
x%5B2%5D+=+%28-%2856%29-sqrt%28+3428+%29%29%2F2%5C-1+=+57.2745623366089

Quadratic expression -1x%5E2%2B56x%2B73 can be factored:
-1x%5E2%2B56x%2B73+=+%28x--1.27456233660889%29%2A%28x-57.2745623366089%29
Again, the answer is: -1.27456233660889, 57.2745623366089. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-1%2Ax%5E2%2B56%2Ax%2B73+%29






logarithm/114659: I have tried everything and I just don't understand this problem.
Here is the problem
log%286%2C36%29 = 5x+%2B+3

1 solutions

Answer 83429 by edjones(7569) About Me  on 2007-12-04 21:59:33 (Show Source):
You can put this solution on YOUR website!
log(6)36=(5x+3)
36=6^(5x+3)
6^2=6^(5x+3)
Since the base (6) is the same for all exponents we can make an equation of the exponents:
2=5x+3
5x=-1
x=-1/5
Check:
2=5*-1/5+3
2=-1+3 true
Ed


Functions/114661: This question is from textbook Beginning Algebra
If f(x) = 4x - 3, find the following:
f(-1)
Can you show me how to figure this, I do not understand.
Thank you.
1 solutions

Answer 83426 by edjones(7569) About Me  on 2007-12-04 21:45:53 (Show Source):
You can put this solution on YOUR website!
f(-1) means x=-1
f(-1)=-4-3=-7
Ed


Polynomials-and-rational-expressions/114625: Find the GCF.
(6y squared - 3y)(y + 7)
1 solutions

Answer 83411 by edjones(7569) About Me  on 2007-12-04 20:36:01 (Show Source):
You can put this solution on YOUR website!
(6y squared - 3y)(y + 7)
=3y(2y - 1)(y + 7)
Ed


Exponential-and-logarithmic-functions/114640: This is a composition of Functions problem

If f%28x%29=x%5E2-4 andg%28x%29=+sqrt%28x%2B4%29 find (f0g)(x)
So I put f(g(x))
=+f%28sqrt%28x%2B4%29%29%5E2-4%29
= now I am stuck, do I add it all together or leave it like that??
1 solutions

Answer 83405 by edjones(7569) About Me  on 2007-12-04 20:25:40 (Show Source):
You can put this solution on YOUR website!
You did the hard part.
=+f%28g%28x%29%29=%28sqrt%28x%2B4%29%29%5E2-4%29
=x+4-4
=x
Ed


Unit_Conversion_Word_Problems/114636: If a document that is 6 inches long is traveling 250 inches per seconds past a transport sensor,how long in milliseconds will the sensor be covered?
1 solutions

Answer 83400 by edjones(7569) About Me  on 2007-12-04 20:13:34 (Show Source):
You can put this solution on YOUR website!
6/250=.024 sec=24 m sec


Linear_Equations_And_Systems_Word_Problems/114639: A 17 foot ladder leans against a building and reaches a height of 14 feet on the building. The bottom of the ladder is how far away from the bottom of the building?
1 solutions

Answer 83399 by edjones(7569) About Me  on 2007-12-04 20:06:40 (Show Source):
You can put this solution on YOUR website!
a=14 c=17
a^2+b^2=c^2
14^2+b^2=17^2
196+b^2=289
b^2=289-196
b^2=93
b=sqrt(93)=9.64 ft... from the building.
Ed


Numeric_Fractions/114604: I am trying to help my son and struggling a little since I have not looked at this stuff in years. Please help me so that I can help him.
Solve
1) -11/12 = 3h/4
2) -7 = m/4
3) 9/14a = 3/7
4) 3/5a = -6
These are the questions he missed on a recent test and I am not able to properly explain how to solve.




1 solutions

Answer 83398 by edjones(7569) About Me  on 2007-12-04 19:58:46 (Show Source):
You can put this solution on YOUR website!
In all of these, if you multiply both sides time the LCD your troubles are over to eliminate the fraction(s) your troubles are over.
.
1)
-11/12 = 3h/4 LCD=12
-11=9h
h=-11/9 divide each side by 9.
.
3)
9a/14=3/7 I assume this is the problem. 14 is LCD.
9a=6
a=6/9=2/3
.
I'll let you do the other two.
.
Ed


Equations/114610: Rewrite the equation –8x – 5y = –45 as a function of x.
1 solutions

Answer 83394 by edjones(7569) About Me  on 2007-12-04 19:44:42 (Show Source):
You can put this solution on YOUR website!
–8x – 5y = –45
-8x+8x-5y=8x-45
-5y=8x-45
-5y/-5=8x/-5-45/-5
y=-8x/5 +9
Ed


Linear-systems/114632: Find an equation of the line described. Write the equation in standard form.
Through (4,8) perpendicular to the y-axis


The equation is? ____ (Type your answer in standard form.
1 solutions

Answer 83392 by edjones(7569) About Me  on 2007-12-04 19:39:03 (Show Source):


Polynomials-and-rational-expressions/114634: The figure shows the graph of f(x)=6x-10/2x-a, find the value of a.
1 solutions

Answer 83389 by edjones(7569) About Me  on 2007-12-04 19:36:22 (Show Source):
You can put this solution on YOUR website!
f(x)=6x-10x/2-a I assume this is the problem.
-a=f(x)-6x+5x subtract 6x-10x/2 from each side.
a=6x-5x-f(x) divide each side by -1.
Ed


Percentage-and-ratio-word-problems/114626: Four brothers decided to buy a stereo that cost $280. Their contributions were in the ratio of 4:2:3:5. What was the largest single contribution in dollars?
1 solutions

Answer 83387 by edjones(7569) About Me  on 2007-12-04 19:28:50 (Show Source):
You can put this solution on YOUR website!
2+3+4+5=14
280/14=20
.
20*(4:2:3:5)=80:40:60:100
.
Ed


expressions/114623: This question is from textbook
Evaluate the discriminant b^2-4ac. Then use the answer to state how many real-number solutions exist for the equation. y=x^2+8x+16

1 solutions

Answer 83386 by edjones(7569) About Me  on 2007-12-04 19:22:35 (Show Source):
You can put this solution on YOUR website!
a=1, b=8, c=16
b^2-4ac=64-4*1*16
=64-64=0
There is only one real number solution.
If the discriminent was negative there would be none and if it was positive there would be two.
x^2+8x+16=0
(x+4)(x+4)=0
x=-4
Ed
graph%28500%2C500%2C-10%2C10%2C-10%2C10%2Cx%5E2%2B8x%2B16%29


Radicals/114609: 8 SQRT. 75 + 3 SQRT. 12 - 5 SQRT. 48
1 solutions

Answer 83385 by edjones(7569) About Me  on 2007-12-04 19:10:18 (Show Source):
You can put this solution on YOUR website!
8 SQRT. 75 + 3 SQRT. 12 - 5 SQRT. 48
=8sqrt(25*3)+3sqrt(4*3)-5sqrt(16*3)
=40sqrt(3)+6sqrt(3)-20sqrt(3)
=26sqrt(3)
Ed


logarithm/114399: Solve: log(subscript 6)x + log(subscript 6)(x-5) = 2
1 solutions

Answer 83289 by edjones(7569) About Me  on 2007-12-04 01:32:45 (Show Source):
You can put this solution on YOUR website!
log(6)x+log(6)(x-5)=2
log(6)(x(x-5))=2
log(6)(x^2-5x)=2
x^2-5x=6^2
x^2-5x-36=0
(x-9)(x+4)=0
x=9 is the only answer because neg. numbers are not in the domain of logs.
Ed


percentage/114465: 2mg equals how many millileters
1 solutions

Answer 83285 by edjones(7569) About Me  on 2007-12-04 01:11:55 (Show Source):
You can put this solution on YOUR website!
If it is water: 2mg=2ml


Graphs/114456: Solve the inequality: x^2 - 10x - 24 < 0
1 solutions

Answer 83283 by edjones(7569) About Me  on 2007-12-04 01:07:25 (Show Source):
You can put this solution on YOUR website!
f(x)<0 when 2 < x < 12
See the graph.
Ed
graph%28500%2C500%2C-5%2C15%2C-50%2C10%2Cx%5E2-10x-24%29