Questions on Algebra: Quadratic Equation answered by real tutors!

Tutors Answer Your Questions about Quadratic Equations (FREE)

Question 391717: Use the quadratic formula to solve the equation.
2x^2-x=-7
The solution set is { }
Click here to see answer by MathLover1(20849)

Question 391717: Use the quadratic formula to solve the equation.
2x^2-x=-7
The solution set is { }
Click here to see answer by ewatrrr(24785)

Question 391733: Ok so i've done this problem at least 20 times and i don't know what i am doing wrong! The work seems to be right, but every time that i have done it, it does not check out properly. Please help!
Question: If the square of a positive number is decreased by twice the number the result is 15. Find the number.
Thank you!
Click here to see answer by stanbon(75887)

Question 391761: Find the x-intercepts of the graph of the equation:
y = x^2 - 1
i really need your help asap thanx :)
Click here to see answer by ewatrrr(24785)

Question 391760: Find the x-intercepts of the graph of the equation:
y = x^2 - 1
i really need your help asap thanx :)
Click here to see answer by ewatrrr(24785)

Question 391816: several books are on sale at a bookstore. some of these books cost 3 dollars , while other cost 5 dollars. one day last week, 80 of these books were sold. the total amount of sales was 300 dollars. how many of each type was sold?
1. write the equations that would solve the system
2show and explain how you solved the problem
3 how do you know you have the correct solution

Click here to see answer by stanbon(75887)

Question 391830: A rectangular skating rink measuring 30m by 20m is doubled in area by adding a strip at one end of the rink and a strip of the same width along one side of the rink. Find the width of the strips if the enlarged rink is still rectangular.
I tried to set up: (x+20)(x+30)=1200 Got x=10 ??? Not sure??
Click here to see answer by rfer(16322)

Question 391855: Need help with this problem: w^2+6w+9
Click here to see answer by stanbon(75887)

Question 391900: An angry construction worker throws his wrench downward from a height of 128 feet with an initial velocity of 32 feet per seconds is givin S(t) = -16t^2 - 32t + 128.
A)what is the height of the wrench after 1 second?
B) H ow long does it take for the wrench to reach the ground?
Click here to see answer by stanbon(75887)

Question 391868: Solve the equation
(u - 3)^2 = 2u^2 - 3u - 9
for u.
(If there is more than one solution, separate them with commas.)
Click here to see answer by jsmallt9(3758)

Question 391840: During a manufacturing process, a metal part in a machine is exposed to varying temperature conditions. The manufacturer of the machine recommends that the temperature of the machine part remain below 135�F. The temperature T in degrees Fahrenheit x minutes after the machine is put into operation is modeled by T=-0.005^2 + 0.45x + 125.

a. Tell whether the temperature of the part will ever reach or exceed 135�F. Use the discriminant of a quadratic equation to decide.

b. If the machine is in operation for 90 minutes before being turned off, how many times will the temperature of the part be 134�F?

Click here to see answer by jsmallt9(3758)

Question 391828: A submarine travelling in a parabolic arc ascends to the surface. The path of the submarine is described by y=2x^2-10x-40,where x represents the time in minutes and y represents the submarine's depth in metres.
a)How deep in the submarine initially? I think 40m.
b)What maximum depth does it reach? Solve algebraically.I think -52.5m.
c)How long does it take the submarine to reach the maximum depth? I think 2.5 seconds.
d)For how long is the submarine underwater?I think 7.625 minutes.
I would really appreciate any help:)
Click here to see answer by ankor@dixie-net.com(22740)

Question 391876: I don't understand this question. please help me. thank you for your time.
Hat sizes are determined by measuring the circumstances of one's head in either inches or centimeters?
Use ratio and proportion to complete the following table.
Hat size
7 1/4
Head circumference (to nearest 1/5 inch)
22 4/5
Head circumference (to nearest centimeter)
58
Hat size
7 1/8
Head circumference (to nearest 1/5 inch)
____ ??
Head circumference (to nearest centimeter)
____?

Click here to see answer by ewatrrr(24785)

Question 391829: 1) Write the equation of the parabola in Standard Form that an x-intercept of (2,0) and a vertex at (6,8). Not sure how to set up:(
2)Solve for x: [(3)/(3-x)] + [(4)/x+2)]=4. I think -3+-sqrt681/-8 ??

Click here to see answer by ewatrrr(24785)

Question 392013: how would you graph the following parabola?:
f(x)=-1/10x^2+6
Click here to see answer by josmiceli(19441)

Question 392051: how do you solve (step-by-step) and graph (as a parabola) the following equation?:
y= -1/10x^2+6
Click here to see answer by Earlsdon(6294)

Question 391709: Julie is about to ride down a waterslide at a local waterpark. Julie's path can be modeled by the equation y=-16x^2+64 , where x is the time on the slide measured in minutes and y is the height of the slide measured in feet.
How long is Julie on the waterslide?
After 30 seconds
After 1 minutes
After 2 minutrs
Click here to see answer by richard1234(7193)

Question 392114: find real solutions
2x - 5 sqrt x + 2 = 0

Click here to see answer by richard1234(7193)

Question 392187: Originally a rectangle was twice as long as its wide. When 5 m was subtracted from its length and 3 m was subtracted from its width, the new rectangle had an area of 55m. Find the dimensions of the NEW rectangle. ( not the old dimensions )
Please show work clearly for me to understand.
Thanks :D
This is what I tried:
Let length = 2x-5
Let width = x-3
( 2x-5) ( x- 3 ) = 55
2x^-6x-5x+15=55
2x^-11x+15=55
2x^-11x-40=0
Now im stuck on this part. Please help.
Click here to see answer by stanbon(75887)

Question 392210: I want to know the formula that show the product of two consecutive integers that equals 72. Thanks
Click here to see answer by Earlsdon(6294)

Question 392210: I want to know the formula that show the product of two consecutive integers that equals 72. Thanks
Click here to see answer by ewatrrr(24785)

Question 392208: I find no factoring for 27r2 - 72 = 0. I want to know how the answer of 0=0 is calculated? Thanks.
Click here to see answer by Earlsdon(6294)

Question 392246: sir pls help me to solve this prblm.A train travels at a certain average for a didtance of 63km and then travels a distance of 72km at an average speed of 6km/hr more than its original speed.if it takes 3 hours to complete the total journey,what is its original average speed.kindly send me the solution to rexi_2004@yahoo.co.in
Click here to see answer by stanbon(75887)

Question 392297: Write each function in vertex form:
y=x^+9x+8
I tried:
y=(x^+9x+20.25)+8+20.25
y=(x+29.25)+28.25
y=-2x^+5x
not sure on this one
Click here to see answer by Alan3354(69443)

Question 392297: Write each function in vertex form:
y=x^+9x+8
I tried:
y=(x^+9x+20.25)+8+20.25
y=(x+29.25)+28.25
y=-2x^+5x
not sure on this one
Click here to see answer by stanbon(75887)

Question 392296: how would you write this equation? " 10 more that two-thirds of x is y "
Click here to see answer by Alan3354(69443)

Question 23: what are the roots if in ractored form it is y=(2x-3)(3x+4)?
what is the axis of symmetry?
Click here to see answer by twilightlover(1)

Question 392424: Solve for x.
3x^2 - 11x = - 6
(If there is more than one solution, separate them with commas.)
Click here to see answer by nerdybill(7384)

Question 392420: Solve for y, where y is a real number.

If there is more than one solution, separate them with commas
Click here to see answer by nerdybill(7384)

Question 392420: Solve for y, where y is a real number.

If there is more than one solution, separate them with commas
Click here to see answer by robertb(5830)

Question 392412: Find the x intercepts of
f(x) = 3x^2 -15x -13
Click here to see answer by nerdybill(7384)

Question 392395: The sum of the squares of three consecutive integers is 434. Find the integers. please show all of your work. Thank you!
Click here to see answer by Alan3354(69443)

Question 392451: 1)a natural number,when increased by 12 becomes equal to 160 times its reciprocal.find the number
Click here to see answer by richard1234(7193)

Question 392535: how to solve quadratic system by graphng
Click here to see answer by richard1234(7193)

Question 392538: how do i solve...
directions: write a quadratic equation with the given roots. Write the equation in the form of ax^2+ bx + c = 0, where a, b, and c are integers
1, 4
-2,-5
-1/3, -3
if you can help me...can u show me how to do the work so that i can see the process
Click here to see answer by Alan3354(69443)

Question 392503: 4x2 - 4x + 3 = 0
Click here to see answer by haileytucki(390)

Question 392422: Write in simplified radical form by rationalizing the denominator.

Click here to see answer by emargo19(101)

Question 392714: y^2-12y=0
What is the answer please. And can you show all work. Thank you!
Click here to see answer by Alan3354(69443)

Question 392750: I was given the following equation to solve with the value of t = 5, v = 20 meters/second and k = 30 meters:
S = -5t^2 + v*t + k
Would you please help me? Using my variables, I came up with the following answer:
S=107
Thanks!
Michele
Click here to see answer by rfer(16322)

Question 392808: The equation S= -5t^2 + v*t + k, using this equation, do you multiply 5t then square it, or square the t then multiply??
thanks
Click here to see answer by checkley79(3341)

Question 392792: can you explain the quadratic equation? its so confusing!
Click here to see answer by richard1234(7193)

Question 392966: what is the solution set for the quadratic equation x^2+6x-3=0?
Click here to see answer by jim_thompson5910(35256)

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