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

Tutors Answer Your Questions about Linear-systems (FREE)

Question 355016: one alloy contains 80% gold (in weight) and another alloy contains 55% gold. how many grams of each alloy should be contained to make a 40kg of an alloy that contains 70% gold?
Click here to see answer by mananth(12270)

Question 354992: I am supposed to solve the systems of equation in three variables.
5x+2y=4
3x+4y+2z=6
7x+3y+4z=29
Click here to see answer by Edwin McCravy(8880)

Question 355693: can you help me solve this? 2/t=t/4t-6. I cannot get the correct answer of (6,2)
Click here to see answer by Fombitz(13828)

Question 356136: perimeter of a rectangle is 204 inches. the length exceeds the width by 62 inches. what is the length and width?
Click here to see answer by mananth(12270)

Question 356133: -7/2x is equal to or greater than -1/4
Click here to see answer by nyc_function(2733)

Question 356127: y-9>2y-2 are 1, -14, -17, -3 soultions
Click here to see answer by edjones(7569)

Question 356118: i 2005, the shabelle river rose an estimated 5.25 inches every 15 hours.the increase in water level is represented by the functon f(x)=5.25, where x is the numbe of hours.
Click here to see answer by Jk22(389)

Question 356253: Solution of Linear Systems by the Echelon Method.
4x-y+3z=-2
3x+5y-z=15
-2x+y+4z=14
And:
x+2y+3z=11
2x-y+z=2
Thank you in advance!
Click here to see answer by Alan3354(30959)

Question 356299: How do i make a system that will have an infinite number of solutions in the y=a+bx form?
Click here to see answer by Fombitz(13828)

Question 356304: Do two linear equalities always have a solution? If not, why not? If yes, under what conditions?

Click here to see answer by Fombitz(13828)

Question 356553: Solve the system algebraically:
x-2y=1
y= sq root of (x-1)
Click here to see answer by stanbon(57222)

Question 356539: Solve the system by the method of substitution.
6x-3y-4=0
x+2y-4=0
Click here to see answer by Alan3354(30959)

Question 356540: Solve the system by the method of substitution.
1/2x + 3/4y = 10
3/4x - y = 4
Click here to see answer by Alan3354(30959)

Question 356646: Please help me solve this equation:
x - 1 < = 5 or x + 3 > = 10
Click here to see answer by stanbon(57222)

Question 356646: Please help me solve this equation:
x - 1 < = 5 or x + 3 > = 10
Click here to see answer by mananth(12270)

Question 356656: I need help with -3(7-3n)+2n=5(2n-4).
Click here to see answer by stanbon(57222)

Question 356658: I need help with -7+8(5-3q)=3(7-9q).
Click here to see answer by rfer(12644)

Question 356654: I need help with 1/3(7x+5)=3x-5.
Click here to see answer by rfer(12644)

Question 356652: I need help with 1/2(8n-2)= -(-8+9n)-5n.
Click here to see answer by rfer(12644)

Question 356653: I need help with 2/3(9n-6)=4(n+1).
Click here to see answer by rfer(12644)

Question 356665: Please teach me how to solve this question.
-3x-4y=2
3x+3y=-3
Click here to see answer by Fombitz(13828)

Question 356725: graph the line with the given slope that contains the given point.
slope=-1/2;(3,1)

Click here to see answer by mananth(12270)

Question 356740: 8x^3-27
Click here to see answer by mananth(12270)

Question 356680: Solve for x, y, and z. Use only linear combination and/or substitution. Do not use matrices.
2x - 12y + 3z = -19
4x + 6y - 2z = 14
6x - 9y - 4z = 13

Click here to see answer by Fombitz(13828)

Question 356861: 0x+y=-2
Click here to see answer by Alan3354(30959)

Question 356671: 1. Compute the Fourier transform of the following signals.
2. (a). x(n) = u(n) – u(n-6)
3. (b). x(n) = 2nu(-n)
4. (c). X(n) = (1/4)nu(n+4)
5. (d). x(n) = (ansin(won)) u(n), |a|<1

Click here to see answer by Fombitz(13828)

Question 356669:
1. Let X(k) denote the N-point DFT of the N-point sequence x(n)
a) If x(n) = – x(N – 1 – n), find X(0) for N even and N odd.
b) If N is even and x(n) = x(N – 1 – n), find X(N/2).

Click here to see answer by Fombitz(13828)

Question 356890: Tickets at a park are $1.50 for kids and $4.00 for adults. On c certain day 2200 people entered the park, and the the admission fees collected totaled $5050. How many children and how many adults were admitted?
Click here to see answer by user_dude2008(1861)

Question 356552: Solve the system algebraically by the substitution method:
y= (x+1)^3
y= sq rt of (x-1)
Click here to see answer by Fombitz(13828)

Question 357006: A mobile phone company offers two monthly calling plans, A and B. Under A, every
minute costs $ 0.10. Under B, the first 100 minutes costs $ 12 and every extra minute costs $ 0.08. What monthly talking time would make B the better choice?
Click here to see answer by mananth(12270)

Question 357129: The function H described by H(x)=2.75+71.48 can be used to predict the height in cm of a woman whose humerus is x cm long Predict teh height of a woman whose humerus is 30cm long
I believe that I am making this harder than it really is but I am so stumped
30(x)=2.75x+71.48
30(x)=74.55
x=2.485
Am I anywhere close
Click here to see answer by jim_thompson5910(28476)

Question 357134: elimination method
4x+5y=2
8x+10y=4

40x+50y=20
40x+-50y=40
80x=40
x=.5
4(.05)+5y=2
2+5y
y=4/5

Not quite sure if this is correct Can you help me please
Click here to see answer by user_dude2008(1861)

Question 357159: How do I find the fourth point for a rectanlge? I can use the other three to find out with a graph, but I do not know how to set up an equation.

Click here to see answer by jim_thompson5910(28476)

Question 282002: Graph this equation.
y=-2x+4

Click here to see answer by jim_thompson5910(28476)

Question 357149: Train A and B are traveling in the same direction on parallel tracks. Train A is traveling at 100 miles per hour and Train B is traveling at 104 miles per hour. Train A passes a station at 11:10 am. If train B passes the same station at 11:40 am at what time will train B catch up to train A
_____am or _______pm

Can some one please help me. Not sure on how to set up the equation
Click here to see answer by checkley77(12569)

Question 357184: 5/4x+1/8x=3/8+x Can I please have some one help me
Click here to see answer by neatmath(300)

Question 357097: The larger of two numbers is 8 times the smaller. If the larger number exceeds the smaller by 56, find the numbers.
Click here to see answer by neatmath(300)

Question 357301: Hi Guys, really struggling with this question.
Given the Cartesian equation of a circle in the form
x^2+y^2+8x-8y+16=0
Find by completing the squares, the centre coordinates of the circle and its radius, Hence sketch the graph of the circle taking care to label the x-axis and y-axis and the origin.
Click here to see answer by ewatrrr(10682)

Question 357417: In need of assistance problem solving: 4/5x=16 m/-3=10 4/5x=16
Click here to see answer by edjones(7569)

Question 357467: whats the slope of the line with these points (2,5)(6,8)
Click here to see answer by nerdybill(6948)

Question 357470: When the digits of a two-digit number are reversed, the new number is 9 more than the original number, and the sum of the digits of the original number is 13. What is the original number?
Click here to see answer by ankor@dixie-net.com(15624)

Question 357672: 3x-2y=15
x+y=1
Click here to see answer by mananth(12270)

Question 357712: Airplane Speed:
Two planes start from the same airport and fly in opposite directions. The second plane starts 1/2 hour after the first plane, but its speed is 80 kilometers per hour faster. Find the groundspeed of each plane if 2 hours after the first plane departs the planes are 3200 kilometers apart.
I am assuming that the distance = rate x time equation will be used, but I am lost.
Click here to see answer by scott8148(6628)

Question 357749: The trip of the Amazon River in canoes and back to the mouth of the Amazon took 12 hours. Going upstream, the canoes traveled at 5km/h, but downstream they traveled 10 km/h faster. how far upstream did they go?
Click here to see answer by mananth(12270)

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