Questions on Algebra: Quadratic Equation answered by real tutors!

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Question 836283: For what value(s) of k will the equation kx^2+(k+1)x-1=0 have exactly one solution?
My teacher has never taught us this. Please help!
Click here to see answer by jim_thompson5910(35256)

Question 836304: I have sent in my graph and solutions to my school and they sent my work back saying my vertex was wrong. The equation is -3x^2-6x-5. I had (0,-5) as my vertex and I can't figure out why its wrong or what else it could. Please help.

Click here to see answer by jim_thompson5910(35256)

Question 836332: The perimeter, P, of a rectangular concrete slab is 46 m and it's area, A, is 90 m^2. Use the formula P + 2l + 2w. Determine the dimensions of the slab. Show your work.
I have tried to do this and keep getting the most ridiculous answers. This question has really stumped me and I have come to a stand still.
Click here to see answer by jim_thompson5910(35256)

Question 836646: A rectangular garden is surrounded by a walk of uniform width. The area of the garden is 180 square yards. If the dimensions of the garden plus the walk are 16 yards by 24 yards, find the width of the walk.
Click here to see answer by josgarithmetic(39617)

Question 836700: 4x^2+1=3x
Click here to see answer by doodles(24)

Question 836698: x^3+9x^2-x-9=0
Click here to see answer by doodles(24)

Question 837528: The profit of an organization is calculated by the function P(x)=x^2-4000x + 7800000 where x is the number of units sold. If the net profit 3800000, find the number of items sold.
Click here to see answer by lwsshak3(11628)

Question 837796: If alpha,beta are the roots of the equation 2x^2+5x+k=0. Find the value of k if alpha^2+beta ^2+alpha*beta=21/4
Click here to see answer by richard1234(7193)

Question 838035: Dear Algebra.com tutors
I am having a lot of trouble with graphing quadratic functions. Such as x squared + 4x - 8, what are good ways to find points besides finding the axis of symmetry and the y-vertex. My main trouble is finding a something good that works to substitute into.
Sincerely Jamie H. a struggling 8th grader
Click here to see answer by Alan3354(69443)

Question 838151: what is the solution set of x^2- 6x +7=0
Click here to see answer by josgarithmetic(39617)

Question 838362: A ball dropped from the top of tower A can be modeled by the function h(t) = -9.8t^2 + 400, where t is the time after it is dropped and h(t) is its height at that time. A ball dropped from the top of tower B can be modeled by the function h(t) = -9.8t^2 + 200. What transformation describes this change? what does this transformation mean?
Click here to see answer by stanbon(75887)

Question 838361: The equation is h(t)= -16t^2+50t+4. (h for feet and t for seconds). The question is When will the ball be 40 feet above the ground. I plugged 40 into h(t), subtracted it and inserted it into the other side. I factored but got t=9/8 and t=2. I do not think I am supposed to have two positive numbers.
Click here to see answer by josgarithmetic(39617)

Question 838355: The equation is h(t)= -16t^2+80t. (h for feet and t for seconds). The question asks how much time it takes for the ball to reach 96 feet. I tried plugging 96 in for h(t) and then subtracting it and inserting it on the other side. I factored, but got t=3 and t=2. I don't think I am supposed to get two positive numbers.
Click here to see answer by richwmiller(17219)

Question 838750: PLEASE HELP
Answer the following for the given quadratic function.
f(x)=x^2+8x+16
a. what is the vertex (h,k) of f. (h,k)=
b. what is the axis of symmetry
c. what are the intercepts
d. do a graph to support your answer
e. on what interval is f increasing
f. on what interval is f decreasing

Click here to see answer by Alan3354(69443)

Question 837918: The value of a machine depreciates according to the function f(x)= 2000(1/2)^x where x is the time in years from the purchase of the machine. find its value aftrer 3 years.
Click here to see answer by Fombitz(32388)

Question 838449: A race has two parts, an 18km run and a 30km canoe race. The canoeists travelled 8km/h faster than the runner. The winning time was exactly 3h. How fast did the runner travel?

Click here to see answer by ankor@dixie-net.com(22740)

Question 838176: A sequence of diagrams is formed by drawing equilateral triangles, each side is 1 cm.
They give me 3 diagrams.
1. Triangle
2. Big triangle with smaller on inside ( makes 4 triangles - 9 lines)
3. Big with smaller triangles ( 18lines)
Question:
The formula for the TOTAL number of one cm lines needed to draw ALL OF THE FIRST n DIAGRAMS is an^3+bn^2+n
Find the values of a and b
Click here to see answer by KMST(5328)

Question 838893: 0=3x^2-17x-34
find the value of x.
Click here to see answer by Fombitz(32388)

Question 839273: You are on a ski-lift 50 feet high. While the lift is stopped to let people off ,you accidentally knock your keys out of your pocket. They fall out of the seat towards the ground.
I'm suppose to write a vertical motion model for the path of the keys and find how long it'll take it to hit the ground.
I have 0= -16t^2 + vt + 50 but I don't know what to
Do next.
Click here to see answer by Alan3354(69443)

Question 839418: What two numbers give me the product of -2240 and the sum of 16?
Click here to see answer by Alan3354(69443)

Question 839474: Given that the quadratic equation x^2-3x+1=0 has 2 different roots, create a quadratic equation, so that each of its roots will be 1 more than the corresponding root of the given quadratic equation.
Click here to see answer by josh_jordan(263)

Question 839475: Given that the quadratic equation x^2-2x-5=0 has 2 different roots, and a second quadratic equation has 2 roots, each of which 2 less than the corresponding root of the given quadratic equation. If the second quadratic equation is x^2+ax+b=0, find the value of a and b.
Click here to see answer by mananth(16946)

Question 839719: when twice a number is subtracted from the square of the number, the result is 99. determine the number
Click here to see answer by Theo(13342)

Question 839761: The equation of the axis of symmetry of the graph of a quadratic function is x= 3. The graph passes through the points R(3, 7) and T(-1, -25). Determine an equation of the function.
Click here to see answer by Fombitz(32388)

Question 839785: Find all values of c such that the equation 39 x2 + 49 x + c = 0 has exactly one solution.
Click here to see answer by LinnW(1048)

Question 839553: If the quadratic formula is used to find the solution set of 3x 2 + 4x - 2 = 0, what are the solutions?
Click here to see answer by LinnW(1048)

Question 839904: solve the following system of equations. y=(y-2)^2 -4 y= -1/2
Click here to see answer by stanbon(75887)

Question 839960: Y=2x^2+2x-4 find vertex form
Click here to see answer by josgarithmetic(39617)

Question 840162: The supply function for a product is
2p − q − 20 = 0,
while the demand function for the same product is
(p + 10)(q + 30) = 6600.
Find the market equilibrium point.
(q, p) =
Click here to see answer by richwmiller(17219)

Question 840288: Two ships start out the same point. One ship travels X miles directly due east, and the other ship travels X miles directly due south. The ship that is traveling to the East travels another 7 miles in the easterly direction, while the other, southerly traveling ship, travels an additional 15 miles south, in the same period of time. What distance X did the ships travel initially, if there distance from each other in the end is 51.22 miles?
Click here to see answer by ankor@dixie-net.com(22740)

Question 840386: Solve the following quadratic equation for the indicated variable.
y2 − 3y = 9x
for y
Click here to see answer by josgarithmetic(39617)

Question 840469: So, I need help getting walked through the steps of the quadratic equation. If a=1 , b=2.2 x10^-2 and c=-1.2 x10^-4, how does x= 4.5x10^-3?
I got as far as -2.2x10^2 + or - square root of 9.64x10^-4 and then don't know what to do or if it is right. PLEASE HELP!! I need to get comfortable with the quadratic equation. Thank you!
Click here to see answer by josgarithmetic(39617)

Question 840519: Express f(x) in the form a(x − h)2 + k.
f(x) = −
3
4
x2 + 15x − 77

Click here to see answer by Fombitz(32388)

Question 840520: Find the standard equation of a parabola that has a vertical axis and satisfies the given conditions.
vertex (6, −5), x-intercept −1

Click here to see answer by ewatrrr(24785)

Question 840431: FInd the exact solution(s) of each system of equations
x^2-y^2=-8
y=2x+1

Click here to see answer by Fombitz(32388)

Question 840479: Steve traveled 600 miles at a certain speed. Had he gone 20mph faster, the trip would have taken 1 hour less,. Find the speed of his vehicle
Click here to see answer by richwmiller(17219)

Question 840522: An object is projected vertically upward from the top of a building with an initial velocity of 96 ft/sec. Its distance s(t) in feet above the ground after t seconds is given by the equation
s(t) = −16t2 + 96t + 120.
(a) Find its maximum distance above the ground.
s(t) = ft
(b) Find the height of the building.
Click here to see answer by josmiceli(19441)

Question 840783: Can you help me solve the quadratic equation x(x-3)/2=5? I have tried subtracting 5 to get the problem to equal zero, but then I got stuck at x(x-3)/-3.
Click here to see answer by Fombitz(32388)

Question 840773: http://imgur.com/wLihix5
I'm completely stumped. Please help me!
Click here to see answer by Fombitz(32388)

Question 840888: a motor boat takes 2 hours more to cover a distance 30 km upstream than it takes to cover the same distance down stream if speed of stream is 2 km/hr then find the speed in still water.
Click here to see answer by hamsanash1981@gmail.com(151)

Question 840870: Factories completely : (2x^2+xy-y^2)+2x-y
Click here to see answer by Fombitz(32388)

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, 17551..17595, 17596..17640, 17641..17685, 17686..17730, 17731..17775, 17776..17820, 17821..17865, 17866..17910, 17911..17955, 17956..18000, 18001..18045, 18046..18090, 18091..18135, 18136..18180, 18181..18225, 18226..18270, 18271..18315, 18316..18360, 18361..18405, 18406..18450, 18451..18495, 18496..18540, 18541..18585, 18586..18630, 18631..18675, 18676..18720, 18721..18765, 18766..18810, 18811..18855, 18856..18900, 18901..18945, 18946..18990, 18991..19035, 19036..19080, 19081..19125, 19126..19170, 19171..19215, 19216..19260, 19261..19305, 19306..19350, 19351..19395, 19396..19440, 19441..19485, 19486..19530, 19531..19575, 19576..19620, 19621..19665, 19666..19710, 19711..19755, 19756..19800, 19801..19845, 19846..19890, 19891..19935, 19936..19980, 19981..20025, 20026..20070, 20071..20115, 20116..20160, 20161..20205, 20206..20250, 20251..20295, 20296..20340, 20341..20385, 20386..20430, 20431..20475, 20476..20520, 20521..20565, 20566..20610, 20611..20655, 20656..20700, 20701..20745, 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