Questions on Algebra: Systems of Linear Equations answered by real tutors!

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Tutors Answer Your Questions about Linear-systems (FREE)


Question 2732: I am studing the substitution Method.. and for some reason i can not seem to figure out how to do it. My teacher has been trying to work with me, but yet when I look at the problem I go blank on what to do.
I have an equation y = 2x + 7
y = 10x - 1 I dont understand how to do this...

Click here to see answer by xcentaur(357) About Me 

Question 2961: I am trying to solve a linear system by elimination but am coming up with a problem. At least I think it is a problem.
2x-5y=11
3x+y=8
I will multiply by (3) and (-2) to get 6x and -6x
(3)2x-5y=11
(-2)3x+y=8
6x-5y=11
-6x-y=8
subtract 5y+1y=6y
11 + 8 =19
6y=19
When I divide 19 by 6 I get 3.16. What did I do wrong????? Please help.
Thank you so much. Tricia

Click here to see answer by indiangangsta(5) About Me 

Question 3069: I'm tring to get thru college math and is having a hard time understanding equations and inequalities please help
one of the problems is 8x-(3x+2)=3x-10

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Question 3023: how do u do graphs for the follwing equation:
x-y=4
x+y=2

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Question 3050: My paper says i should solve this equation by substitution: 2x + 3y = 13
y = 3 - 2x
could you show me how to sleve this step by step
My paper also says solve this equation by elimination: 3x - y = 4
7x + 2y =18
could you also solve that step by step

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Question 3046: im trying to get ready for a math test but i dont understand problems like these at all there systems
{y=2x-7
{y=5-x

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Question 3046: im trying to get ready for a math test but i dont understand problems like these at all there systems
{y=2x-7
{y=5-x

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Question 3000: How to solve linear systems in 4 varibles.
for example:
W + X +Y + Z = 3
W - X + Y + Z = 1
W + X - Y + Z = 1
W + X + Y - Z = 3
___________________

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Question 3154: y=3x +5 whats the slope? whats the y-intercept?
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Question 3372: How do u solve systems of equations by elimination. Help its for my mid-term review sheet.
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Question 3401: Which system should be used for:
5x-y=1
10x-2y=2

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Question 3412: Are these lines paralell, perpendicular or neither? -2X +Y=10 and 4X-Y=5. show all workings
thanks

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Question 2483: for solve for y
1. y-3x=7
2. 2x+y=5
solve for a
a+3b=-2

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Question 3551: solve the following system by any means you like, explain your answer: 2x+5z=5, x-3y+2z+=2, 3x+y+3z=3
Click here to see answer by longjonsilver(2297) About Me 

Question 3841: Solve using the sustitution method:
11x-6y=494
x+7y=-23

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Question 3865: linear equation. Does this have a solution? If not why? If so why?
24x + 10y = 4000
5y = -12x + 8000

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Question 3862: substitution method? Can someone please help!
x+7y= -39
-3y-2y= 22

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Question 3869: Sorry Jon!
It is
x + 7y = -39
-3x - 2y = 22
Substitution method ,I can't get it to work out.

Click here to see answer by longjonsilver(2297) About Me 

Question 4158: How do I solve an equation such as x+4y=8 or 3x-5y=16,to determine whether the given points, (0,2) and (2,2) are the solutions to the given equation? Also how would I determine the value of b so that the point given is a solution point of the equation, such as (3,0), 2x-y=b or (-5,6), 3x-2y=b?
Click here to see answer by Earlsdon(6287) About Me 

Question 4066: 2x-8y=16
-x+4y=-8

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Question 4178: solve the following system of linear equations:
3x-2y+4z=1
x+y+2Z=3
2x-3y+6z=8

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Question 4179: Need another soloution to the question previously asked
Solve the following system of equations
3x-2y+4z=1
x+y+2z=3
2x-3y+6z=6
I previously did not understand your answer and per your advisement is seeking another solution (in other words had not idea what you were "talking about") :-)

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Question 4483: when solving linear equations with 3 variables, how do you know which one is the easiest to solve for?
Click here to see answer by pushpaharan(47) About Me 

Question 5428: In 7 years Deac will be twice as old as Irina. Four years ago he was three times as old as Irina was then. How old are each of them now?
I can not figure out how to set up the equations! The book says the answers are: Deac is 37 and Irina is 15. I do not come up with those ages. I have been using: x = Deac, y = Irina x + 7 = 2y and x - 4 = 3y. Help! What am I doing wrong? Thank you - Janette

Click here to see answer by rapaljer(4667) About Me 

Question 5779: I really don't understand this question:
The cost to rent a car is given by the formula C= 50d + 0.2k,
where d = the number of days rented
and
k= the number of km driven.
Lin has $300 to spend on car rental for her 4 day holiday. How far can she travel on this holiday?

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Question 5869: What is the difference between parallel and coincide?
example: 18=18

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Question 5871: Please help me solve this equation using the two-point slope formula:(-2,3);(5,-3) and how to check your answer if its correct or not.thank you so much.
Click here to see answer by ichudov(499) About Me 

Question 5893: Okay here is the question.
Take a look at the table below and write out an equation for f(x).
x -2 -1 0 1 2
f(x) -5 -2 1 4 7
Now. Here is what I thought might be right. Follow the y2-y1/x2-x1 and put in some numbers. So I put in 7-4/2-1 which = 3/1
So then the equation I got was y=(3/1)x+b
Is that the correct answer? I don't really know whether or not I found what was specified. Thank you for all your help.

Click here to see answer by longjonsilver(2297) About Me 

Question 5887: Suppose you have a lemonade stand, and when you charge $1 per cup of lemonade you sell 60 cups. But when you raise your price to $2 you only sell 30 cups. Write an equation for the number of cups you sell as a function of the price you charge. Denote "C" for number of cups, and "P" for the price you charge. Assume the function is linear.
I know this may seem really easy, but I have been looking at it forever and I can't figure it out. I want to help my cousin with his homework but it's above my head. Thanks for all your help.


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Question 5794: I am having difficulty solving this problem 4x-4yis greater than or equal to 8. My solution is as follows: ___-4y is greater than or equal to 4x-8 both sides divided by 4 and my answer is y is less than or equal to -2
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Question 6018: y = 4x + 2; y = 4x + b find the value of b
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Question 6062: 24x+5=12x+41
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Question 6017: y + 2 =mx; 8x -2y = -1 find the value of m
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Question 6128: Solve the following equation for A:
AC - 2AB = 3BC
I have no clue. Any help is greatly appreciated. Thank you

Click here to see answer by Earlsdon(6287) About Me 

Question 6156: The whole third variable thing confuses me. When I try and do it by substitution I always end up with this long chain that I don't know how to reduce to find the answer for the second variable. Thanks in advance.
Solve for X, Y and Z
22X + 5Y + 7Z = 12
10X + 3Y + 2Z = 5
9X + 2Y + 12Z = 14

Click here to see answer by glabow(165) About Me 

Question 6287: the value of k for which 2x%5E2%2B5xy%2B3y%5E2%2B3x%2B4y%2Bk=0represent a pair of straight lines
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Question 6184: can you solve this equation by breaking the equation by step?
The Equation is 3/2x=4=-9

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Question 6301: Problem Solving Using Systems of Equations
I purchased tickets to an air show for 5 adults and 2 children. The total cost was 162. The cost of a child's ticket was $3 less than the cost of an adult's ticket. Find the price of an adult's ticket and a child's ticket.

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Question 6299: decide if elimination and substitution can be used to solve any system

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Question 6311: Problem Solving Using Systems of Equations
Julie and Eric row their boat(at a constant speed) 55 miles downstream for 5 hours, helped by the current. Row at the same rate, the trip back against the current takes 11 hours. Find the rate of the current.

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Question 6381: Find the equation of line which is perpendicular to the line y = x + 1 and passes the point (1,3)
I need HELP!!!!!! Thank you. If possible an immediate response would be greatly appreciated. Thank you again.

Click here to see answer by Earlsdon(6287) About Me 

Question 6390: can you solve these problems in steps?
Set2
1. solve the equation 5x+3=-15, for x if y=0.
2. Find the x-intercept for the equation 6x-y=-12
3. determine the equation of the line with slope -3 and containing(-7,2)
4. Given the following,write an equation in standard form. The line y-intercept 5 and slope2.
9. find the slope for the equation x-2y=6.
10.for the equation x-2y=6, is the point(4,-1) on the line
Set3
7. a brownie recipe that makes 36 brownies calls for 1 1/2 cups of sugar. How many cups of sugar are needed to make 24 brownies?
Set4
1. write an example of quadratic trinomial?
2. Perform the indicated operations: (7x to the 3rd power-5x+2)-(5x to the 3rd power-4x to the 2nd power +6x-7)
3. multiply 6xto the 2nd power(5x-3)
4. multiply(5a-3)(2a+4)
5. simplify (3x to the 2nd Power)(-2xto the 5th power)
6. simplify (5a b to the 3rd power)to the 2nd power
7. simplify (4a to the 3rd power)to the 2nd power (3a) to the 2nd power
8. simplify 10x to the 5th power y to the 4th power
15x to the 3rd power y to the 9th power
9. multiply (x-3) to the 2nd power
10. multiply (a-4)(a+4)
Set5
1. Factor completely: x to the 2nd power - 7x-30
2. Factor completely : x to the 2nd power + 4x-16
3. Factor completely 2x to the 2nd power - 11x +5
4. Factor completely 4x to the 2nd power + 20x-24
5. Factor completely 4m to the 2nd power - 9
6. Factor completely 16a to the 2nd power- 25b to the 2nd power
7. solve by factoring: x to the 2nd power - x - 12 = 0
8. solve by factoring: 2c to the 2nd power -5 = -9c
9. solve the equation(x+6)(x-7)(x-8)(x+9)=0
10. find the dimensions of the rectangle if the width is 3 feet less than the length and the area is 40ft to the 2nd power.
Set6
1 simplify: 3x - x+5
x+4 x+4
2.simplify: 6x x 10y
5y 8x
9. solve by the quadric formula : 2x to the 2nd power + 10x + 25 =9
10. solve: x to the 2nd power +10x +25=9

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Question 6419: can you please help me with my problem. its about System of Linear Equations in three variables,

A Dependent system of three equations:
2x - 3y - z = 4 (1)
-6x + 9y + 3z = -12 (2)
4x - 6y - 2z = 8 (3)

please help..

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Question 6471: Hi there,
I am confronted with the following question:
"A job takes 4 hrs for two people working together. If one person works alone he can do the job in 6 hrs. How long will it take the other person working alone to complete the job?"
I don't really know how to approach this question. It seems so simple yet I can't seem to figure out why the answer is 12 hrs. Please help me out.
Thanks in advance,
Mike

Click here to see answer by Earlsdon(6287) About Me 

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, 10756..10800, 10801..10845