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elima answered: 1432 problems
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Miscellaneous_Word_Problems/108754: A family made a trip by car.
They traveled 1312 km in 3 days.
On the 2nd day, they traveled 2 times the number of km from the 1st day.
On the 3rd day, they traveled 98 km less than the 2nd day.
Find the distance traveled every day.
1 solutions

Answer 79324 by elima(1433) About Me  on 2007-11-08 13:42:37 (Show Source):
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A family made a trip by car.
They traveled 1312 km in 3 days.
On the 2nd day, they traveled 2 times the number of km from the 1st day.
On the 3rd day, they traveled 98 km less than the 2nd day.
Find the distance traveled every day.
===========================================
x= first day travel
2x=2nd day
2x-98=3rd day
==========================
x+2x+2x-98=1312
5x=1312+98
5x=1410
x=282
================
first day = 282
2nd day= 2(282)=564
3rd day = 564-98=466
:)


Probability-and-statistics/108600: a girl has 24 quarters and dimes. togther they had up to 3.60 how many quarters does she have?
1 solutions

Answer 79174 by elima(1433) About Me  on 2007-11-07 14:57:26 (Show Source):
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a girl has 24 quarters and dimes. togther they had up to 3.60 how many quarters does she have?
q+d=24
.25q+.1d=3.60
=====================
d=24-q
.25q+.1(24-q)=3.60
.25q+2.4-.1q=3.60
.15q=3.6-2.4
.15q=2.4
q=8
================
8+d=24
d=24-8
d=16
:)


Numbers_Word_Problems/108520: The sum of two numbers is 42. One number plus 2 times the other number is 57. What are the numbers?
The sum of two numbers is 45. Their difference is 9. What are the numbers?

1 solutions

Answer 79169 by elima(1433) About Me  on 2007-11-07 14:31:50 (Show Source):
You can put this solution on YOUR website!
The sum of two numbers is 42. One number plus 2 times the other number is 57. What are the numbers?
x+y=42
x+2y=57
Lets solve by elimination;
so we will multiply the first equation by -1;
(-1)x+y=42
-x-y=-42
==========
Now we will add that equation to the second;
cross%28-x%29-y=-42
cross%28x%29%2B2y=57
_________
y=15
now plug that into either original equation to find x;
x+15=42
x=27
========================================
The sum of two numbers is 45. Their difference is 9. What are the numbers?
x+y=45
x-y=9
Since one variable will already be eliminated we will not need to multiply anything;
x%2Bcross%28y%29=45
x-cross%28y%29=9
_____________
2x=54
x=27
plug that into either equation for x;
27+y=45
y=45-27
y=18
:)
_________


Polynomials-and-rational-expressions/108507: (m^2-5mn + 3n^2)(m^2+4mn - 2n^2)
Please help me solve this.
1 solutions

Answer 79163 by elima(1433) About Me  on 2007-11-07 14:03:51 (Show Source):
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(m^2-5mn + 3n^2)(m^2+4mn - 2n^2)
=======================================

m%5E4%2B4m%5E3n-2m%5E2n%5E2-5m%5E3n-20m%5E2n%5E2%2B10mn%5E3%2B3m%5E2n%5E2%2B12mn%5E3-6n%5E4
Now collect like terms;
m%5E4%2B4m%5E3n-5m%5E3n-2m%5E2n%5E2-20m%5E2n%5E2%2B3m%5E2n%5E2%2B10mn%5E3%2B12mn%5E3-6n%5E4
m%5E4-m%5E3n-19m%5E2n%5E2%2B22mn%5E3-6n%5E4
:)


Polynomials-and-rational-expressions/108487: Solve. 5(x – 5) + 8x = 9x – 25
1 solutions

Answer 79160 by elima(1433) About Me  on 2007-11-07 13:33:46 (Show Source):
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5(x – 5) + 8x = 9x – 25
distribute the 5;
5x-25+8x=9x-25
13x-25=9x-25
13x-9x=-25+25
4x=0
x=0/4
x=0
:)


Polynomials-and-rational-expressions/108486: Solve. 5(x – 9) – 4x = x – 7
1 solutions

Answer 79159 by elima(1433) About Me  on 2007-11-07 13:31:09 (Show Source):
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5(x – 9) – 4x = x – 7
distribute the 5;
5x-45-4x=x-7
x-45=x-7
x-x=38
The x's cancel out, there is no solution
:)


Linear-systems/108482: Solve the system by addition.
4x – 6y = –1
8x + 3y = 3

1 solutions

Answer 79157 by elima(1433) About Me  on 2007-11-07 13:28:13 (Show Source):
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4x – 6y = –1
8x + 3y = 3
==============
This is also called elimination, you want to eliminate one of the variables.
So we will try to eliminate the x, so I will multiply the first equation by -2,
(-2)4x-6y=-1
-8x+12y=2----new equation
Now lets take the new equation and add it to the original second;
cross+%28-8x%29%2B12y=2
cross+++%288x%29%2B3y=3
_________
15y=5
y=5%2F15
y=1%2F3
Now we will plug y=1/3 into one of the original equations for y;
4x-6(1/3)=-1
4x-2=-1
4x=1
x=1/4
check:
4(1/4)-6(1/3)=-1
1-2=-1
:)


Miscellaneous_Word_Problems/108217: carol,ava and cindy swim at a public pool each day . one day carol swam twice as many laps as ava and cindy swam three more laps than ava. if the women swam 27 laps together, how many laps did each swim?
1 solutions

Answer 79090 by elima(1433) About Me  on 2007-11-06 21:10:28 (Show Source):
You can put this solution on YOUR website!
carol,ava and cindy swim at a public pool each day . one day carol swam twice as many laps as ava and cindy swam three more laps than ava. if the women swam 27 laps together, how many laps did each swim?
=========================
x=carol
y=ava
z=cindy
==============
x=2y
z=y+3
=============
x+y+z=27
2y+y+y+3=27
4y+3=27
4y=27-3
4y=24
y=6
=============
So Ava swam 6 laps
Carol = 2(6)=12
Cindy=6+3=9
:)


Inequalities/108206: Graph each inequalities
y<1/2x+2
x-3y<9
1 solutions

Answer 79088 by elima(1433) About Me  on 2007-11-06 21:05:24 (Show Source):
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y<1/2x+2
x-3y<9
=================
first lets put both in slope-intercept form;
the first one already is;
y<1/2x+2
===============
x-3y<9
-3y<-x+9
y>1/3x-3
Now lets graph, the lines are going to be dashed;
The red line is the first equation, you are going to shade the area below the line(don't forget the line is dashed)
The green is the second equation and shade the area above the line(line is dashed)
:)
graph+%28400%2C400%2C+-5%2C5%2C-5%2C5%2C+%281%2F2%29x%2B2%2C+%281%2F3%29x-3%29


Graphs/108407: solve following systems by substitution
4x-12y=5
-x+3y=-1
x=-3y+1


4(1-3y)+12y=5
4-12y+12y=5
4x=5
Double checking to see if I did these right.

1 solutions

Answer 79082 by elima(1433) About Me  on 2007-11-06 20:54:51 (Show Source):
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The answer is going to be , no solution. When it is worked out, you cancel both variables.
You are close;
4x-12y=5
-x+3y=-1
=================
-x=-1-3y
x=1+3y
================
4(1+3y)-12y=5
4+12y-12y=5
4%2Bcross%2812y%29-cross%2812y%29=5
4=5
no solution
:)


Linear-systems/108384: Given f(x) = –x3 – 3x2 + 3x + 7, find f(–1), f(0), and f(2)
1 solutions

Answer 79078 by elima(1433) About Me  on 2007-11-06 20:41:08 (Show Source):
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Given f(x) = –x^3 – 3x^2 + 3x + 7, find f(–1), f(0), and f(2)
f%28-1%29=-%28-1%29%5E3-3%28-1%29%5E2%2B3%28-1%29%2B7
f%28-1%29=1-3-3%2B7=2
f%280%29=-%280%29%5E3-3%280%29%5E2%2B3%280%29%2B7
f%280%29=0-0%2B0%2B7=7
f%282%29=-%282%29%5E3-3%282%29%5E2%2B3%282%29%2B7
f%282%29=-8-12%2B6%2B7=-7
:)


Graphs/108403: solve the following systems by substitution
5x-2y=-5
y-5x=3

5x-2(5+3)=-5 y=5(3)+3
5x-10x+3=-5 =15+3
-5x=-15 =18
x=3
Just double checking to see if I did these right.
1 solutions

Answer 79076 by elima(1433) About Me  on 2007-11-06 20:31:50 (Show Source):
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Not quite;
5x-2y=-5
y-5x=3
===============
we will go ahead and solve the second equation for y;
y-5x=3
y=3+5x
=============
now put that in for y in the first equation;
5x-2(3+5x)=-5
5x-6-10x=-5
-6-5x=-5
-5x=-5+6
-5x=1
x=-1/5
================
Now plug that in the equation and solve for y;
5(-1/5)-2y=-5
-5/5-2y=-5
-1-2y=-5
-2y=-4
y=2
=============
:)


Volume/108353: The volume od an octagonal prism is 486 cubic millimeters. If the area of the base is 54 square millimeters, what is the height of the prism?
1 solutions

Answer 79071 by elima(1433) About Me  on 2007-11-06 20:10:17 (Show Source):
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The volume of an octagonal prism is 486 cubic millimeters. If the area of the base is 54 square millimeters, what is the height of the prism?
======================
Formula for volume;
V=BH
B= area of base;
486=54H
486/54=h
h=9
:)


Polynomials-and-rational-expressions/108351: This question is from textbook Elementary and intermediate algebra
im not understanding how to do this work.
1 solutions

Answer 79067 by elima(1433) About Me  on 2007-11-06 20:02:08 (Show Source):
You can put this solution on YOUR website!
You need to post the problem, we do not all have the same book
:)


Expressions-with-variables/108237: how do solve for the linear combination?
1 solutions

Answer 79064 by elima(1433) About Me  on 2007-11-06 19:53:42 (Show Source):
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Linear combination would also be elimination method, you add two equations together;
2x+2w=48
x-2w=12
--------
3x=60
x=20
Then you substitute x in either equation for 20 and solve for w;
2(20)+2w=48
40+2w=48
2w=8
w=4
:)


Linear_Algebra/108241: how do solve for the linear combination method
1 solutions

Answer 79062 by elima(1433) About Me  on 2007-11-06 19:51:57 (Show Source):
You can put this solution on YOUR website!
Linear combination would also be elimination method, you add two equations together;
2x+2w=48
x-2w=12
--------
3x=60
x=20
Then you substitute x in either equation for 20 and solve for w;
2(20)+2w=48
40+2w=48
2w=8
w=4
:)


decimal-numbers/108247: write 6.25as a mixed nummer.then subtract 5/8 from the mixed number.what is the difference?
1 solutions

Answer 78875 by elima(1433) About Me  on 2007-11-05 21:04:04 (Show Source):
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write 6.25as a mixed nummer.then subtract 5/8 from the mixed number.what is the difference?
6%281%2F4%29-%285%2F8%29
25%2F4-5%2F8
50%2F8-5%2F8
45%2F8
5%285%2F8%29
:)


Linear-systems/108215: a train averaged 36 miles per hour and took 8 hours to travel from chicago to st.louis. what is the distance between chicag and st.louis?
1 solutions

Answer 78871 by elima(1433) About Me  on 2007-11-05 20:54:49 (Show Source):
You can put this solution on YOUR website!
a train averaged 36 miles per hour and took 8 hours to travel from chicago to st.louis. what is the distance between chicag and st.louis?
let x be amount of miles from Chicago to St.Louis;
1%2F36=8%2Fx
x=288
:)


Linear_Equations_And_Systems_Word_Problems/108214: Find the x-intercept of x - 2y = 9.
1 solutions

Answer 78870 by elima(1433) About Me  on 2007-11-05 20:51:41 (Show Source):
You can put this solution on YOUR website!
Find the x-intercept of x - 2y = 9.
To find the x-intercept, just make y=0;
x-2(0)=9
x-0=9
x=9
:)


Equations/108210: Please put this into equation form: 400 tickets total sold to game. Student tickets are $2, adults $3. Total $ collected is $1050. I know that the answer is 150 student tix and 250 adult tix, but I need this in equation form.Please help.
1 solutions

Answer 78866 by elima(1433) About Me  on 2007-11-05 20:28:25 (Show Source):
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400 tickets total sold to game. Student tickets are $2, adults $3. Total $ collected is $1050.
s+a=400
2s+3a=1050
:)


Proportions/108207: solve each proportion.
1 solutions

Answer 78865 by elima(1433) About Me  on 2007-11-05 20:24:13 (Show Source):
You can put this solution on YOUR website!
You need to post the problem, we do not all have that same book
:)


Finance/108205:
1 solutions

Answer 78863 by elima(1433) About Me  on 2007-11-05 20:22:27 (Show Source):
You can put this solution on YOUR website!
You need to post the problem, we do not all have that book
:)


Money_Word_Problems/108197: shawn has an annual interest income of $3290 from two investments. he has $7000 more invested at 8% than he has invested at 6%. find the amount invested in each rate ?
1 solutions

Answer 78862 by elima(1433) About Me  on 2007-11-05 20:21:27 (Show Source):
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shawn has an annual interest income of $3290 from two investments. he has $7000 more invested at 8% than he has invested at 6%. find the amount invested in each rate ?
=======================================
.08x+.06y=3290
y=x+7000
-------------------
.08x+.06(x+7000)=3290
.08x+.06x+420=3290
.14x=2870
x=20500
.08(20500)+.06y=3290
1640+.06y=3290
.06y=1650
y=27500
===================
At 8% interest = $20500
at 6%interest = $27500
:)


Graphs/108193: find values for m and b in the following system so that the solution to the system is (-3,4)
5x+7y=b
mx+y=22

5(-3)+7(4)=13
-6(-3)+4=22
Is this all the steps or am I missing something?
1 solutions

Answer 78860 by elima(1433) About Me  on 2007-11-05 20:09:55 (Show Source):
You can put this solution on YOUR website!
You are correct, with what you give that's all you can do.
:)


Graphs/108191: x+5y=10
-2x-10y=-20

2x+10y=20
-2x-10y=-20
0 = 0
Just double check to make sure this is right?

1 solutions

Answer 78859 by elima(1433) About Me  on 2007-11-05 20:07:10 (Show Source):
You can put this solution on YOUR website!
Great job. you are correct!
:)


Graphs/108190: Solve following systems by addition
2x+3y=1
5x+3y=16

2x+3y=1
-5x-3y=-16
-3x=-15
x=-5
Double checking to see if these are right?

1 solutions

Answer 78858 by elima(1433) About Me  on 2007-11-05 20:06:01 (Show Source):
You can put this solution on YOUR website!
The answer is +5, negative divided by a negative gives you a positive. Your doing everything else correct. Good Job. Just watch your signs.
:)
2x+3y=1
-5x-3y=-16
-3x=-15
x=5


Graphs/108185: Solve the following systems by graphing.
2x-y=4
2x-y=6


y=(4-2x)
y=(6-2x)
y=10
Am I doing this right?
1 solutions

Answer 78857 by elima(1433) About Me  on 2007-11-05 20:02:13 (Show Source):
You can put this solution on YOUR website!
Solve the following systems by graphing.
2x-y=4
2x-y=6
you need to put them in slope intercept form and graph;
2x-y=4
-y=-2x+4
y=2x-4
--------------
2x-y=6
-y=-2x+6
y=2x-6
:)
graph+%28400%2C400%2C+-5%2C5%2C-5%2C5%2C+2x-4%2C+2x-6%29


Exponents/108183: This question is from textbook little red riding hood
7x--3x
1 solutions

Answer 78856 by elima(1433) About Me  on 2007-11-05 19:58:16 (Show Source):
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7x-(-3x)=10x
:)


Inequalities/108182: Which number does not make the number sentence 26 + y> 30 true?
A. 10 B. 4 c. 7 d. 100
1 solutions

Answer 78855 by elima(1433) About Me  on 2007-11-05 19:55:06 (Show Source):
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Which number does not make the number sentence 26 + y> 30 true?
A. 10 B. 4 c. 7 d. 100
===================================
If you plug 4 in for y;
26 +4>30
it is untrue, because it = 30 it is not greater than
:)


Graphs/108036: Solve and graph the solution set. 3(x – 4) > 7x – 9
1 solutions

Answer 78805 by elima(1433) About Me  on 2007-11-05 11:41:31 (Show Source):
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3(x – 4) > 7x – 9
3x-12>7x-9
3x-7x>-9+12
-4x>3
x<-3/4
number_line+%28600%2C+-6%2C6%2C-3%2F4%29
Since the inequality is less than, you will circle -3/4 and make a line from the circle going left on the number line.
:)


Linear-systems/108048: This question is from textbook Algebra 1
use substitution to solve each system of equations. if the systemdoes not have exactly one solution,state whether it has no solution or infintely many solutions?
1 solutions

Answer 78804 by elima(1433) About Me  on 2007-11-05 11:28:06 (Show Source):
You can put this solution on YOUR website!
You should post the problem, we do not all have that book
:)