Questions on Algebra: Quadratic Equation answered by real tutors!

Tutors Answer Your Questions about Quadratic Equations (FREE)

Question 352771: Can you please help me understand how to do this problem.
Solve for X
x^2 - x + 11 = 0 so x = ?
I came up with this answer and I am unsure if it is correct.
1 + sqrt43 over 2
1 - sqrt42 over 2

Click here to see answer by jim_thompson5910(28715)

Question 352873: there are currently 20 members in a school's ski club and the dues are $8 per member. to encourage the recruiting of new members, the club treasurer suggests that for each new member recruited, the dues for all members be reduced by 10 cents
a) how much membership money will the club have if it recruits 10 new members? 15 new memers? N new members?
b) for what value of N will be the club's total membership money be a maximum??
please help i am clueless in how to solve this problem thanks!!
Click here to see answer by scott8148(6628)

Question 353035: f(x)=8-x^2
I got
Vertex (0, x^2)
Line of Symmetry x=0
Max/Min -x^2
Value of, f(0)=8 max/min
I choose max.
What I cannot figure out is how do I graph this one?
Click here to see answer by stanbon(57967)

Question 353026: Algebra: Find the vertex, symmetry, maximum, and minimum of f(x)=-x^2+12x+1.
Click here to see answer by robertb(4012)

Question 353039: Find vertex, line of symmetry, max/min value of the quadratic function, and graph the function.
f(x) = -2x^2+2x+9
x-coordinate of the vertex is?
y-coordinate of the vertex is?
the equation of the line of symmetry is x=?
Max/min of f(x) is ?
The value, f(1/2)=19/2 is the minimum or maximum?
Click here to see answer by solver91311(17077)

Question 353037: Solve 6x+x(x-3)=0
Find the x-intercepts of f(x) = 6x+x(x-3)
Solutions in ordered pair.
x-intercept in ordered pair.
Click here to see answer by edjones(7569)

Question 353139: Solve the quadratic equation 3x2 + 5x + 2 = 0 by factoring
Click here to see answer by Fombitz(13828)

Question 353174: factor completely:
2x^2-20x+50-18y^2=0
Click here to see answer by CharlesG2(828)

Question 353174: factor completely:
2x^2-20x+50-18y^2=0
Click here to see answer by ewatrrr(10682)

Question 353193: How do I use the quadratic formula to solve this x^2-3x=-6 ?
Click here to see answer by ewatrrr(10682)

Question 353221: find the vertex, the line of symmetry and the maximum or minimum value of f(x). Graph the function
f(x)=1/2(x+3)^2+3?
Click here to see answer by stanbon(57967)

Question 353348: list an equation that models the following characteristics:
Graph is a parabola that opens up
vertex is loctaed at (-73,26)
Click here to see answer by edjones(7569)

Question 353418: Solve the quadratic equation by completing the square:
4(x)^2 – 12(x) – 55 = 0
4(x)^2 – 12(x) = 55
4(x)^2 – 3(x) = 55
(x)^2 – 3(x) = 55/4

I know I have to add (b/2)^2 to both sides of the equation, which I calculated as 9/4...or do I keep this as (3/2)^2?
(x^2 – 3x + 9/4) = (55/4 + 9/4)
(x^2 – 3x + 9/4) = 16
And this is where I get lost. There seem to be so many different ways this is done and I can't figure out what my goal is. I've been trying to figure this out for a while and could use a little guidance. Thanks for your time :-)
Click here to see answer by edjones(7569)

Question 353431: can you help with answers to these two for me please
first ....
5(-m-3)+4m-10= if m=5
second...
-w-5+5(-5w+9)= if w=1
Click here to see answer by stanbon(57967)

Question 353398: If f(x)=ax^2+bx+c
Show that (f(x-h)-f(x))/h = 2ax+ah+b
Click here to see answer by jsmallt9(3296)

Question 353347: list the vertex for each parabola modeled by these second-degree equations. Be sure to include both coordinates of the vertex in each response. y=3(x-5)^2-8
Click here to see answer by jsmallt9(3296)

Question 353571: what is the difference between solving equation by factoring and equation using tsbles? can you please give me an example thankyou.. Yuli
Click here to see answer by Alan3354(31518)

Question 352806: A rectangle has a perimeter of 42 feet. The length is 3 feet longer than the width . What is the lenght and width of the deck
Click here to see answer by sofiyac(695)

Question 353641: The x-intercepts of a parabola are (-5,0) and (3,0). Determine the x- coordinate of the vertex.
Click here to see answer by Fombitz(13828)

Question 353342: provide a sketch of the graph for the following wquation. be sure the graph clearly indicates the location of the vertex. y-20=(x-54)^2
Click here to see answer by Fombitz(13828)

Question 353349: list an equation that models the following characteristics
graph is a parabola that opens down
vertex is located at (0,84)
graph is wider that the graph of y=x^2
Click here to see answer by Fombitz(13828)

Question 353639: The president of a company producing water pumps has gathered data suggesting that the average cost in dollars of producing x units per hour of a new style of pump will be c(x)=x^2-22x+166. Determine the number of pumps per hour to produce to keep the average cost below $75 per pump.
Click here to see answer by josmiceli(9817)

Question 353786: solve by completing the square
x^2-4x=10
x=
type exact answer using radicals as needed
Click here to see answer by solver91311(17077)

Question 353789: solve by completing the square
x^2+7x-30=0
what is the solution for x?? use commas to separate as needed
Click here to see answer by josmiceli(9817)

Question 353795: The sum of the base and height of a triangle is 16 inches. If the area of the triangle is 30 square inches, what is the length of the base and height?
Click here to see answer by mananth(12270)

Question 353792: Solve x^2+7x-10=0

what are the solutions for x?
Click here to see answer by mananth(12270)

Question 353827: A man deposited $2000 in a savings bank paying him a certain interest. At the end of the year he withdraw $150. At the end of the second year the amount dew to him was $1947.50. What was the rate of interest?
Click here to see answer by mananth(12270)

Question 353839: solve for r
r^2+3r=6
type an exact answer using radicals as needed
Click here to see answer by Alan3354(31518)

Question 353840: Leah and Gellie can finish a project in 4 hours if they worked together. If it would take Leah 6 hours more than Gellie to finish the project alone, how long would Leah need to finish the project working alone? (Show your solution using Quadratic Equation)
Click here to see answer by stanbon(57967)

Question 353838: Solve for X

x^2+12x+4=0
Click here to see answer by Alan3354(31518)

Question 353843: Find the area of a right triangle whose legs have lengths which differ by 7 meters and whose hypotenuse is 17 meters long. (Show your solution using Quadratic Equation)
Click here to see answer by nerdybill(7003)

Question 353837: Solve a) x^2+7x-10=0

b)find the x intercepts of f(x)=x^2+7x-10

type exact answers using radicals as needed. rationalize all denonminators.
Click here to see answer by Edwin McCravy(8999)

Question 353828: A stone was dropped over the edge of a cliff, and 8 seconds later, its sound of striking the ground was heard. How high is the cliff, if the velocity of sound is 1120 feet per second?
Click here to see answer by josmiceli(9817)

Question 353842: The length of a rectangle is 5 times its width. The area is 86 square meters. Find the length of the rectangle. (Show your solution using Quadratic Equation)
Click here to see answer by ewatrrr(10682)

Question 353882: 1. A rectangle has a perimeter of 100 feet. Express its area in terms of one of its sides, x.
Click here to see answer by ewatrrr(10682)

Question 353894: I have a hard exponent quadratic question.
5x^2/3 + 2x^4/3 -13 =0
My first inclination was to rearrange the terms to...
2x^4/3 + 5x^2/3 -13 =0
This puts it in the right order for substitution / y= x^2/3
Thus... 2y^2 + 5y -13 =0
This is where I'm stuck. I don't know how to unfold the answer with the unusual powers.
Thanks for your help.
Neil
Click here to see answer by Earlsdon(6294)

Question 353887: I have a problem that are driving me crazy. The problem has a quadratic solution, but for the life of me I can't figure it out. Please help!
5(3x-4)^6 + 7(3x-4)^3 -23 =0
I set it up by substitution / y= (3x-4)^3
This gives me the form 5y^2 + 7y -13 =0
My problem is not knowing how to "unfold" the problem after I've done the alternate equation.
Thanks for your help
Click here to see answer by jim_thompson5910(28715)

Question 353963: I'm a little confused on how to work this one...
4x^4 - 12x^2 - 19 = 0
I use subtitution of y = x^2 giving me
4y^2 - 12y - 19 = 0
My answers are y = 4.145751311 and -1.145751311
Now I'm not sure what to do from here.
Thanks a lot for your help!
Neil
Click here to see answer by jim_thompson5910(28715)

Question 353969: Earlier I asked for help to solve this.
5(3x-4)^6 + 7(3x-4)^3 -23 = 0
The tutor sent back an answer I don't know how to punch into my calculator to get the real number. The form they sent was not in whole number form, but in a form I don't know how to even punch in my calculator yet. Any further help would be great!
Neil
Click here to see answer by jim_thompson5910(28715)

Question 353999: A market vendor sold some goods for $72. His gain per cent was equal to one third of the cost of the goods in pesos. What was the cost of the goods?
Click here to see answer by rfer(12730)

Question 354049: Solve for x
2(x-4)-(x+2)=(x+2)(x-4)

use a comma to separate answers as needed
Click here to see answer by mananth(12270)

Question 354053: give exact and approximate solutions to three decimal places.
x^2+7x-3=0

the exact solutions are x=
Click here to see answer by sofiyac(695)

Question 354051: solve for x
1/x + 1/x+16 = 1/15
Click here to see answer by sofiyac(695)

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