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

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Question 604333: Use scientific notation to perform the calculations. Give the answer in scientific notation and standard notation.
7.2x10^2 / 1.2x10^4
Click here to see answer by josmiceli(19441)

Question 604408: I am working on systems of Linear Equations, solving using the addition method
If it is inconsistent we are to state such, if it is dependent we indicate, x, and answer.
I know this should be simple, I cannot get the hang of it, I tried to follow the book, to no avail.

{ x-7 + y + 9 = 5
--- ----
5 2

x+9 + y-7 = 6
___ ___
2 3
2(x-7) + 5(y+9) = 50
3(x+9) + 2(y-7) = 36
2x + 5y = 19
3x + 2y = 23
5x + 7y = 42
x = 7y + 42 / 5

I really dont know what I am doing or what I should do at this point. I would deeply appreciate assistance. Thank you!

Click here to see answer by mananth(16946)

Question 604420: 8x+5y=-37
6x-5y=-89
Click here to see answer by alicealc(293)

Question 604500: through:(1,2), slope=7
Click here to see answer by alicealc(293)

Question 604612: Determine whether the given pair is a solution of equations. Remember to use alphabetical ordered variables.
(1,9) 7x-y=-2
3x-7y=-60
Click here to see answer by jim_thompson5910(35256)

Question 604614: Solve by the elimination method.

4x-y=25
x+y=15
Click here to see answer by jim_thompson5910(35256)

Question 604606: Solve using the substitution method
3x+5y=19
X=33-7y
Having a hard time grasping the substitution method. Thanks!
Click here to see answer by Alan3354(69443)

Question 604656: what would be the x and y intercepts for the equation 2y=x
Click here to see answer by Alan3354(69443)

Question 604655: what would be the x and y intercepts for the equation x=2y
Click here to see answer by Alan3354(69443)

Question 604609: Solve the system using the substitution method
0.1x+0.3y=1.6
0.8x-0.7y=5.8
Click here to see answer by lwsshak3(11628)

Question 604666: how would i solve the equation x=2y using graphing?
this is the question i meant to ask
Click here to see answer by Alan3354(69443)

Question 604719: Question:
Solve the equations from question 4 to show that the coordinates found in question 3 are the solution of these equations.
Coordinates in question 3: (3,1)
Question 4 equations: AB y= 3/4 -3 CD y=-3 + 10
Many thanks
Click here to see answer by stanbon(75887)

Question 604800: ] Find all values of a for which the following linear system:

a) has no solution, b) has a unique solution, c) has infinitely many solutions.
Solve the linear system for a = 7.

Click here to see answer by Alan3354(69443)

Question 604899: How do I solve systems of equations by substitution for example
x + y =
x - y =
Click here to see answer by AnlytcPhil(1806)

Question 604931: Having trouble please help. solve using elimination method. 3x+4y=-8, 7x-4y=-32
Click here to see answer by scott8148(6628)

Question 604959: My assignment is solve a sytem of equations by using an augmented matrix and elementry row operations: Here are the 3 problems I am having trouble with.
1. y = 2x + 3
y = 4x - 1
2. 8x + 2y = 13
4x + y = 11
3. -x + 1/3y = 5
2x + 3y = 1
Click here to see answer by lynnlo(4176)

Question 605011: The current I in an electrical conductor vary inversely as the resistance R of the conductor. The current is 5 amperes while the resistance is 950 ohms. What is the current when the resistance is 510 ohms?
Click here to see answer by Alan3354(69443)

Question 605100: Choose the equation of teh line that passes through the point (-4,-8) and has a slope of zero.
Click here to see answer by stanbon(75887)

Question 605056: Find the ordered pair which solves this system of equations: 2x-3y=11 and 4x+y=15
Click here to see answer by mananth(16946)

Question 605111: Solve the following system of equations for x:
6x+7y=-8
-6x-14y=22
I need your help please. I can't figure out if there is an answer or if these equations represent parallel lines and there is no solution or if these equations represent the same line and there are infinite solutions.
Thank you so much for your help!!
Click here to see answer by ankor@dixie-net.com(22740)

Question 605118: Choose the number solutions to the following system of equations:
x-3y=3
-5x+15y=-15
This one confuses me. Is there one solution, no solutions, many solutions or cannot be determined? Thanks for any help you can give me.
Click here to see answer by richard1234(7193)

Question 605003: Traffic signs are regulated by the Manual on Uniform Traffic Control Devices. The perimeter of some traffic signs must be 80 inches. Also its length is 8 inches longer than its width. Find the dimensions of this sign.
Click here to see answer by asuar010(338)

Question 605256: 5x^2-3x-8-y=0 how do I solve this and is this a circle, or a parabola?
Click here to see answer by lynnlo(4176)

Question 605318: graph -5x-40y=-30
Click here to see answer by solver91311(24713)

Question 605571: What are the steps to solve this equation:
y = x + 4
3x + y =16

Click here to see answer by solver91311(24713)

Question 605658: Determine whether the ordered pair is a solution of the inequality. (-5,4);2x+y<-3?
Click here to see answer by lawdej(58)

Question 606427: How would you solve a problem like this.
Is this ordered pair a solution of the system of linear equations.
2x+y=3 (0,3)
x-2y=-1
Please show work.

Click here to see answer by richard1234(7193)

Question 606505: solve the elmination method -5x+6y=18
15x-18y=20
Click here to see answer by mananth(16946)

Question 606578: x=w/8+y/8+z/8
solve for y
Click here to see answer by bucky(2189)

Question 606724: For the system of linear equation
-Determine how many solutions exist
-Use either elimination or substitution to find the solutions (if any)
-Graph the two lines, labeling the x-intercepts, y-intercepts, and points of intersection
x + y = 3, y = x + 3
Here is what I have done so far using substitution:
x + y = 3, y = x + 3
x + y = 3
x + y � y = 3 � y
x = 3 � y
3 � y + y = 3 � y
3 = 3 � y
3 � 3 = 3 � 3 � y
y = 0
x + 0 = 3
x = 3
check
x + y = 3
3 + 0 = 3
3 = 3 (It checks here but not in the second equation)
It seems I am getting the reverse of what the answer should be. I have done it many times and I get the same answer. Please help!
Click here to see answer by Alan3354(69443)

Question 606993: i am hoping that you can help me with this linear systems by substitution question y=2x-1
x+5y=28
Click here to see answer by mananth(16946)

Question 606776: 5x-2y=4 Is (-3,8) a solution?
Click here to see answer by asuar010(338)

Question 607098: What is the equation of the line that passes through the point (3, 2) and has a slope of 4
Click here to see answer by nerdybill(7384)

Question 607398: 5x+4y=22
7x+6y=34 Using Matrix Multiplication
Click here to see answer by lynnlo(4176)

Question 607508: 1. Model the following sequence of toothpick figures, Dashes and Stars, with toothpicks and:
a.
Step One: Loop and number each figure and Numerically determine the total number of toothpicks in each figure. Mark your number counts on the figures.
Step Two: Convert your looping ideas into Words.
Step Three: Convert your looping and word ideas into Symbols. Simplify your symbolic equations and check them for n = 1, 2, 3, 4, 5 and 6.
DASHES AND STARS
The figure is: two dashes then a star, dash, star, dash
1 2 3 (numbers underneath figure)
b. How many toothpicks will there be in the 99th Dashes and Stars figure?
c. How many toothpicks will there be in the 100th Dashes and Stars figure?
d. How many toothpicks will there be in the 101st Dashes and Stars figure?
e. For which Dashes and Stars figure are there 84 toothpicks?
f. For which Dashes and Stars figure are there 97 toothpicks?
g. For which Dashes and Stars figure are there 1011 toothpicks?
Please help me with this... Im so confused :(
Click here to see answer by richwmiller(17219)

Question 607507: Model the following sequence of toothpick figures, Rectangles with Pluses, with toothpicks
and:
a.
Step One: Loop and number each figure and Numerically determine the total number of
toothpicks in each figure. Mark your number counts on the figures.
Step Two: Convert your looping ideas into Words.
Step Three: Convert your looping and word ideas into Symbols. Simplify your symbolic
equations and check them for n = 1, 2, 3, 4, 5 and 6.
RECTANGLES WITH PLUSES
fIGURE ONE: I _ _ I fIGURE TWO: I _ _ I_+_I (TWO DASHES ON TOP OF PLUS SIGN TO MAKE TWO SQUARES) fIGURE 3: I _ _ I_+_I__ _I (ALSO TWO DASHES ON TOP OF PLUS SIGN TO MAKE TWO SQAURES)
1 2 3
b. How many toothpicks will there be in the 99th Rectangles with Pluses figure?
c. How many toothpicks will there be in the 100th Rectangles with Pluses figure?
d. How many toothpicks will there be in the 101st Rectangles with Pluses figure?
e. For which Rectangles with Pluses figure are there 124 toothpicks?
f. For which Rectangles with Pluses figure are there 171 toothpicks?
g. For which Rectangles with Pluses figure are there 1009 toothpicks?
Click here to see answer by richwmiller(17219)

Question 607480: What is the answer to solve by the substitution method
7x + 7y = 0
-2x + y = 6
Click here to see answer by richwmiller(17219)

Question 607587: Please solve.
3x = y + 5
x + 2y = 4
My answer is y=1, x=2 (apparently I solve differently than my son's teacher)

Click here to see answer by rfer(16322)

Question 607587: Please solve.
3x = y + 5
x + 2y = 4
My answer is y=1, x=2 (apparently I solve differently than my son's teacher)

Click here to see answer by solver91311(24713)

Question 607695: solve using the substitution method 2x+9y=5 x=4-6y
Click here to see answer by Alan3354(69443)

Question 607840: Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.
6x � 4y = 19
24x - 16y = -76

Click here to see answer by Alan3354(69443)

Question 607867: Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.
6x � 4y = 19
24x - 16y = -76
Click here to see answer by jim_thompson5910(35256)

Question 607875: 7-7/8x greater than or equal to 8
Click here to see answer by lynnlo(4176)

Question 607987: A van starts off with a full tank of gas (13 gallons). The van consumes 1 gallon of gas for every 25 miles it drives. Write a linear equation relating the number of gallons g left in the gas tank as a function of the number of miles m the van has driven.
Click here to see answer by ewatrrr(24785)

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, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790, 11791..11835, 11836..11880, 11881..11925, 11926..11970, 11971..12015, 12016..12060, 12061..12105, 12106..12150, 12151..12195, 12196..12240, 12241..12285, 12286..12330, 12331..12375, 12376..12420, 12421..12465, 12466..12510, 12511..12555, 12556..12600, 12601..12645, 12646..12690, 12691..12735, 12736..12780, 12781..12825, 12826..12870, 12871..12915, 12916..12960, 12961..13005, 13006..13050, 13051..13095, 13096..13140, 13141..13185, 13186..13230, 13231..13275, 13276..13320, 13321..13365, 13366..13410, 13411..13455, 13456..13500, 13501..13545, 13546..13590, 13591..13635, 13636..13680, 13681..13725, 13726..13770, 13771..13815, 13816..13860, 13861..13905, 13906..13950, 13951..13995, 13996..14040, 14041..14085, 14086..14130, 14131..14175, 14176..14220, 14221..14265, 14266..14310, 14311..14355, 14356..14400, 14401..14445, 14446..14490, 14491..14535, 14536..14580, 14581..14625, 14626..14670, 14671..14715, 14716..14760, 14761..14805, 14806..14850, 14851..14895, 14896..14940, 14941..14985, 14986..15030, 15031..15075, 15076..15120, 15121..15165, 15166..15210, 15211..15255, 15256..15300, 15301..15345, 15346..15390, 15391..15435, 15436..15480, 15481..15525, 15526..15570, 15571..15615, 15616..15660, 15661..15705, 15706..15750, 15751..15795, 15796..15840, 15841..15885, 15886..15930, 15931..15975, 15976..16020, 16021..16065, 16066..16110, 16111..16155, 16156..16200, 16201..16245, 16246..16290, 16291..16335, 16336..16380, 16381..16425, 16426..16470, 16471..16515