Questions on Algebra: Quadratic Equation answered by real tutors!

Tutors Answer Your Questions about Quadratic Equations (FREE)

Question 536073: how can i complete the square with:
x^2-10x=11
my answer, (-10x/2)^2 =11 was wrong.
Click here to see answer by nerdybill(7384)

Question 536074: How can i complete the square with :
2k^2 + 4k-10=0
my answer was 5, it's obviously wrong... help plz! thank you
Click here to see answer by nerdybill(7384)

Question 535805: A piggy- bank contains 50 coins, all either 2 cents or 5 cents. The total value of coins is $1.87. How many 2 cents coins are there?
Click here to see answer by april4869(19)

Question 536098: Factor each expression completely
4. x2 � 13x + 42 (1 point)
(x + 6)(x � 7)
(x � 6)(x + 7)
(x � 6)(x � 7)
(x + 6)(x + 7)
5. 64x2 + 144x + 81 (1 point)
(8x � 9)2
(8x + 9)2
2(8x + 9)
(8x + 9)(8x � 9)
6. 3x2 + 5x � 50 (1 point)
(x � 25)(3x + 2)
(3x � 25)(x + 2)
(x � 10)(3x + 5)
(3x � 10)(x + 5)
7. 5k2 � 125 (1 point)
(k � 5)2
5(k � 5)2
(k + 5)(k � 5)
5(k + 5)(k � 5)
8. 15n2 � 8n +1 (1 point)
(5n + 1)(3n + 1)
(5n � 1)(3n � 1)
(5n + 1)(3n � 1)
(5n � 1)(3n + 1)
Click here to see answer by Alan3354(69443)

Question 536196: an express train and local train leave vancouver at 3pm and head for hope 180 kms away. the local train travels two thirds as fast as the express train and arrives 1 hour after the express train. what time does thelocal train arrive in hope?
i have so far
LOCAL: D = R x T
180=2/3R x T+1
EXPRESS: D = R x T
180= R x T
LOCAL: T=180/ 2/3r -1
EXPRESS; T=180/R
I DONT KNOW WHAT THE LCM IS FOR 2/3R AND R ...IS IT 1 2/3 R ? OR r(2/3r)>?<

Click here to see answer by josmiceli(19441)

Question 536262: The roots of a cubic are x=-2,x=3, and x=5. What arethe possible factors of the cubic? Explian your reasoning
Click here to see answer by KMST(5328)

Question 536166: Please help me solve this problem! thank you!
solve each quadratic equation :

16v^2 = 49

or
15s^2 - 8s - 12 = 0

either problem would be a great help! thanks
Click here to see answer by lwsshak3(11628)

Question 536334: what is the ordered pair for 10x - 7y = -6 5x + 7y = 81
Click here to see answer by april4869(19)

Question 536385: Formula D=0.054^2+0.058x describes the distance in feet D that it takes a vehicle traveling x mph to stop on dry pavement.
A. How fast can you drive if you wish to be able to stop within 65 feet?
I have it started with 0.054x^2+0.058x=65. How do I proceed from here?? Please help!
Click here to see answer by lmeeks54(111)

Question 536430: How do you solve this, step by step?
� 1 � - � � 1 � � � � �
___ � � � ___ � � �= �2
x+3 � � � �x-3
* in simplified radical form
Click here to see answer by Alan3354(69443)

Question 536440: 2(8x+1)^2=90
Solve using quadratic formula

Click here to see answer by Maths68(1474)

Question 536439: x^4-9x^2+8=0

Click here to see answer by edjones(8007)

Question 536437: Solve using Quadratic Formula
5x^2+8x-3=0
Click here to see answer by mananth(16946)

Question 536497: the solution of the quadratic equation (15x squared+44 x-3=0) by factorization
Click here to see answer by Earlsdon(6294)

Question 536527: Please help!!!
What quadrant has the solution set to the system x≥0 and y≥0?

1)I
2) II
3) III
4) IV
Click here to see answer by jim_thompson5910(35256)

Question 536583: Solve using the Quadratic Formula:
x^2 + 4x + 6 = 0
Click here to see answer by jim_thompson5910(35256)

Question 536603: A piece of wire is 8 inches long. The wire is cut into two pieces and then each piece if bent into a square. Find the length of each piece if the sum of the areas of these squares is to be 2 square inches.
square 1: x/4 by x/4
square 2: 8-x/4 by 8-x/4
Click here to see answer by fcabanski(1391)

Question 536600: A person standing cloes to the edge on the top of a 200-foot building throws a baseball vertically upward. The quadratic function
s(t)=-16t^2+64t+200
models the ball's height above the ground, s(t), in feet, t seconds after it was thrown.
A)After how many seconds does the ball reach it's maximum height? What is the maximum height?
B)How many seconds does it take until the ball finally hits the ground?
Click here to see answer by Alan3354(69443)

Question 536598: The instructions say solve each equation by factoring, by taking square roots, or by graphing. When necessary,round your answer to the nearest hundredth.
The first problem is x^2-18x-40=0
Click here to see answer by Alan3354(69443)

Question 536619: using the quadratic formula x=[-b(+-)sqrt(b^2-4ac)]/2a
solve quadratic equation
x^2 -5 = 0
Click here to see answer by jim_thompson5910(35256)

Question 536618: The population of fruit flies,p,after day from the first mating of ten flies is given by the function p(n)=0.08x^2+0.11x. Find the population of fruit flies after.
Click here to see answer by fcabanski(1391)

Question 536670: x^2-14x+48<0
The answer choices are: A (4,12), B (6,8), C (-infinity,6) U (8, infinity), D (-infinity,6] U [8, infinity)
Click here to see answer by KMST(5328)

Question 536716: Over a distance of 240km, the average speed of a train is 20km/h faster than that of a car. It takes the car 30 minutes longer to cover the same distance. What is the speed of the car and the speed of the train?
Thank you for any help:)
Click here to see answer by mananth(16946)

Question 536715: Two cyclists leave the same place at the same time but travel in different directions and at different speeds. Cyclists A travels north at a constant speed off x km/h. Cyclist B travels east at a speed 5km/h more than cyclist A. After 1 hour, the cyclists are 37km apart. At what speed is cyclist A traveling?
Thank you:)
Click here to see answer by mananth(16946)

Question 536708: Mary makes a round trip of 150 km each way. Coming back Mary was able to average 25 km per hour faster than she had going. If the total trip took three and a half hours, then what was Mary's speed coming back?
Thank you in advance:)
Click here to see answer by mananth(16946)

Question 536713: A storeowner buys a quantity of tennis ball for $600. If they had each cost $0.25 less, she would have had 10 more for the same money. How much did she pay for each ball?
Thanks:)
Click here to see answer by josmiceli(19441)

Question 536711: If a bus traveled 10km/h faster, it would take 2 hours less time to make a 315km trip. What is its speed?
Thanks for any help:)
Click here to see answer by ankor@dixie-net.com(22740)

Question 536912: Write a quadratic equation in the variable x having the given numbers as solutions. Type the equation in the standard form, ax^2+bx+c=0
Solutions are negative sign (Sqrt) 10, 5 (sqrt) 10. so it would be 5 space square root sign and negative sign space square root sign). I am totally lost on this one. I have no idea how to even begin....
Click here to see answer by richard1234(7193)

Question 536504: One of the roots of the quadratic equation ax2+bx+c=0 is twice the other.Show that 2b2=9ac

Click here to see answer by richard1234(7193)

Question 536915: The performance of a certain stock can be modeled by the equation d(t)=2000(1.2)^t. If (d)t is the amount of money the stock is currently worth, and t is the time in the years after the initial investment, how has the value of the stock changed after 24 months?
(A) It has decreased by $2880.
(B) It has decreased by $120.
(C) It has increased by $400.
(D) It has increased by $880.
(E) It has increased by $2880.
Click here to see answer by fcabanski(1391)

Question 536976: state the value of the discriminant, then describe the nature of the solution of 9x^2-4x+6=0
Click here to see answer by jim_thompson5910(35256)

Question 537021: How do you determine where the solutions are when looking at a graph of a quadratic equation?
Thank you!
Click here to see answer by lwsshak3(11628)

Question 537156: A+Bi
(-5+2i)+(14-3i)
Click here to see answer by jim_thompson5910(35256)

Question 537157: A+Bi
(28+7i)-(-3+5i)
Click here to see answer by jim_thompson5910(35256)

Question 537287: Write a quadratic equation that has integer coefficients and has as solutions the given pair of numbers. (Use x as the variable.)
9 and 1
Click here to see answer by jim_thompson5910(35256)

Question 537452: x^2-7x-60 ???
Click here to see answer by algebrahouse.com(1659)

Question 537452: x^2-7x-60 ???
Click here to see answer by stanbon(75887)

Question 537392: i need help with these problem i have been doing them for days and they are giving me a headache i hope that this isn't to much to ask for. I am problem by factoring.
1. 3a^2+a=a^2+10a+11
2.n(n+3)=70
3.b(5b-4)=12
4.4t^2-9+16=15-4t^2
5.(2k+4)(2k+9)=3^2+11k
6.5+6y(y+2)=5y+8
7.(m-3)^2=64
I know these are a lot of problem but i really tried to solving them and now I'm just giving up. I understand if you don't answer them all and again thank you every much.
Click here to see answer by ankor@dixie-net.com(22740)

Question 537483: 4x + 8y = 7 3x + 4y = 6
Click here to see answer by mananth(16946)

Question 537565: how do you express N=(t^2-t)/2 as a quadratic expression Thank you
Click here to see answer by fcabanski(1391)

Question 537594: B^2-12b+27=0
Click here to see answer by Tatiana_Stebko(1539)

Question 537580: I am having the hardest time with this. Solve by the method of your choice:
(1/x^2-3x+2)=(1/x+2)+(5/x^2-4)
I have tried this different ways and just cant figure it out.
Click here to see answer by bucky(2189)

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, 16516..16560, 16561..16605, 16606..16650, 16651..16695, 16696..16740, 16741..16785, 16786..16830, 16831..16875, 16876..16920, 16921..16965, 16966..17010, 17011..17055, 17056..17100, 17101..17145, 17146..17190, 17191..17235, 17236..17280, 17281..17325, 17326..17370, 17371..17415, 17416..17460, 17461..17505, 17506..17550, 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20746..20790, 20791..20835, 20836..20880, 20881..20925, 20926..20970, 20971..21015, 21016..21060, 21061..21105, 21106..21150, 21151..21195, 21196..21240, 21241..21285, 21286..21330, 21331..21375, 21376..21420, 21421..21465, 21466..21510, 21511..21555, 21556..21600, 21601..21645, 21646..21690, 21691..21735, 21736..21780, 21781..21825, 21826..21870, 21871..21915, 21916..21960, 21961..22005, 22006..22050, 22051..22095, 22096..22140, 22141..22185, 22186..22230, 22231..22275, 22276..22320, 22321..22365, 22366..22410, 22411..22455, 22456..22500, 22501..22545, 22546..22590, 22591..22635, 22636..22680, 22681..22725, 22726..22770, 22771..22815, 22816..22860, 22861..22905, 22906..22950, 22951..22995, 22996..23040, 23041..23085, 23086..23130, 23131..23175, 23176..23220, 23221..23265, 23266..23310, 23311..23355, 23356..23400, 23401..23445, 23446..23490, 23491..23535, 23536..23580, 23581..23625, 23626..23670, 23671..23715, 23716..23760, 23761..23805, 23806..23850, 23851..23895, 23896..23940, 23941..23985, 23986..24030, 24031..24075, 24076..24120, 24121..24165, 24166..24210, 24211..24255, 24256..24300, 24301..24345, 24346..24390, 24391..24435, 24436..24480, 24481..24525, 24526..24570, 24571..24615, 24616..24660, 24661..24705, 24706..24750, 24751..24795, 24796..24840, 24841..24885, 24886..24930, 24931..24975, 24976..25020, 25021..25065, 25066..25110, 25111..25155, 25156..25200, 25201..25245, 25246..25290, 25291..25335, 25336..25380, 25381..25425, 25426..25470, 25471..25515, 25516..25560, 25561..25605, 25606..25650, 25651..25695, 25696..25740, 25741..25785, 25786..25830, 25831..25875, 25876..25920, 25921..25965, 25966..26010, 26011..26055, 26056..26100, 26101..26145, 26146..26190, 26191..26235, 26236..26280, 26281..26325, 26326..26370, 26371..26415, 26416..26460, 26461..26505, 26506..26550, 26551..26595, 26596..26640, 26641..26685, 26686..26730, 26731..26775, 26776..26820, 26821..26865, 26866..26910, 26911..26955, 26956..27000, 27001..27045, 27046..27090, 27091..27135, 27136..27180, 27181..27225, 27226..27270, 27271..27315, 27316..27360, 27361..27405, 27406..27450, 27451..27495, 27496..27540, 27541..27585, 27586..27630, 27631..27675, 27676..27720, 27721..27765, 27766..27810, 27811..27855, 27856..27900, 27901..27945, 27946..27990, 27991..28035, 28036..28080, 28081..28125, 28126..28170, 28171..28215, 28216..28260, 28261..28305, 28306..28350, 28351..28395, 28396..28440, 28441..28485, 28486..28530, 28531..28575, 28576..28620, 28621..28665, 28666..28710, 28711..28755, 28756..28800, 28801..28845, 28846..28890, 28891..28935, 28936..28980, 28981..29025, 29026..29070, 29071..29115, 29116..29160, 29161..29205, 29206..29250, 29251..29295, 29296..29340, 29341..29385, 29386..29430, 29431..29475, 29476..29520, 29521..29565, 29566..29610, 29611..29655, 29656..29700, 29701..29745, 29746..29790, 29791..29835, 29836..29880, 29881..29925, 29926..29970, 29971..30015, 30016..30060, 30061..30105, 30106..30150, 30151..30195, 30196..30240