Questions on Algebra: Quadratic Equation answered by real tutors!

Tutors Answer Your Questions about Quadratic Equations (FREE)

Question 118493: What is S squared - S = 0 ?
Click here to see answer by scott8148(6628)

Question 118494: What is X squared - X =6?
Click here to see answer by scott8148(6628)

Question 118497: 30 + x = X squared ?
Click here to see answer by stanbon(57214)

Question 118497: 30 + x = X squared ?
Click here to see answer by leky28(1)

Question 118496: S squared = -4s ?
Click here to see answer by MathLover1(6611)

Question 118445: The arithmetic sequence x,2x-20,3x-28,... has D1=-16. What is the formula for the nth term ?
I said tn= -16+12 but was marked wrong :(
Click here to see answer by Nate(3500)

Question 118495: R squared =4 ?
Click here to see answer by stanbon(57214)

Question 118504: Solve by completing the square
x^2+8x+13=0
Click here to see answer by stanbon(57214)

Question 118503: Solve using square root property
(x+8)^2=81
Click here to see answer by stanbon(57214)

Question 118502: Solve using square root property
5x^2=100
Click here to see answer by josmiceli(9645)

Question 118511: Solve.
-200p+35000=-p^2+400p-20000. Please help
Click here to see answer by tutor_paul(490)

Question 118529: A rectangular parking lot has dimensions 16 metres by 40 metres. The total area of the parking lot is increased by 512 metres by paving an extra strip of uniform width around the entire lot. How wide is the strip ?
I tried (x+16)(x+40)=640+512 and found x=-64 and x=8 so width must be 8 metres since it cannot be negative but I only got partial marks:(
Click here to see answer by josmiceli(9645)

Question 118533: What is the value of b if 2x^2 + bx + 8 has a discriminant of -15 ?
i said 7 but my teacher marked it wrong !!! I think I should have said -7 or +7 ,can someone please expain this to me ?
Click here to see answer by tutor_paul(490)

Question 118532: For the quadratic equation x^2 + kx +7 =0, if 3+sqrt2 is a root, what is the value of k ?
I said 6 but my teacher marked it wrong. Please help me :)
Click here to see answer by tutor_paul(490)

Question 118531: A flare is fired as a stress signal and its height ,h in metres above the ground, t seconds after firing, is provided in the table below. Algebraically determine the quadratic function that defines the height of the flare above the ground t seconds after firing, and use it to determine the flare's height at 2.4 seconds.
t---0 1 2 3 4
h---2 97 182 257 322
I tried y=-2ak^2
97=-2a(1)^2
97/-2=-2a/-2
a=-48.5 and was completly lost :( Please Help Me :)
Click here to see answer by scott8148(6628)

Question 118534: An arithmetic sequence has t4=4 and t10=5.5. What is the 88th term for the sequence? I said 25 but I only guessed correctly, I don't understand how to do it :(
Click here to see answer by scott8148(6628)

Question 118528: A rectangular lawn has dimensions 30m by 40m. A strip of uniform width is to be placed around the perimeter. How wide should the strip be so that exactly half the lawn gets mowed?
I tried (2x-30)(2x-40) and found x=5m but I was marked wrong by my teacher :(
Click here to see answer by scott8148(6628)

Question 118580:
r^2-r-6/3r-9
Click here to see answer by checkley71(8403)

Question 118583: 4x +8/6x+18 times 5x+15/x^2-4
Click here to see answer by jim_thompson5910(28476)

Question 118551: Simplify the expression.
1a) square root of 54
1b)square root of 72
1c) square root of 5/9
1d) square root of 7/36
1e) square root of 9/11
1f)square root of 9/25
Click here to see answer by jim_thompson5910(28476)

Question 118637: The graph of a quadratic function f is the graph of y=-2x^2 translated 4 units to the left and 6 units down. What is the equation of function f?
Click here to see answer by stanbon(57214)

Question 118639: The perimeter of a rectangle is 100 feet. Let x represent the width of the rectangle and write a quadratic function that expressed the area of the rectangle in terms of its width.
Click here to see answer by ilana(307)

Question 118582: x^2 + 6x +5/9y^2 times 3y/x+1

Click here to see answer by MathLover1(6611)

Question 118651: One number is 10 greater than the other number. Find the two numbers such that their product is a minimum. What is the product?
Click here to see answer by Fombitz(13828)

Question 118654: What term in the sequence (1.6,1.2,0.8,0.4,...) is -38.4 ? I guessed 99 but was marked wrong . I don't know how to do this , please help me :)
Click here to see answer by Fombitz(13828)

Question 118650: A 4 by 6 inch photograph is to be matted such that the area of the mat is double the area of the photo. Assuming that the mat is the same width all around the picture,what is the width of the mat ?
I tried (4-2x)(6-2x) and ended up with (x+4)(x-3)=0 and said witdth of mat was 3 inches but lost marks :( Can anyone explain this problem to me ?

Click here to see answer by checkley71(8403)

Question 118655: What are all possible values of b if 2x^2 +bx= -8 has a discriminant of -15 ? I said 7 but I got it wrong. I don't know how to solve this , can someone please help me ?
Click here to see answer by ankor@dixie-net.com(15622)

Question 118649: A theatre seats 500 people per show and is currently sold out with a ticket price of $16. A survey shows that for every $2 per ticket price increase, 25 fewer tickets will be sold.Write a function to model this situation and use this function to determine the ticket price that will result in the greatest revenue per show.
I tried (25x-500)(2x-16)=0
50x^2-400x-1000x+8000
x^2-28+150
x=-b/a=28/2=$14
BUT lost several marks :( Can anyone tell me why :)
Click here to see answer by Edwin McCravy(8879)

Question 118581: a(a-b)^2/4b times 4b/a(a^2 -b^2 )
Click here to see answer by MathLover1(6611)

Question 118664: explain why a^0 =1 for any nonzero value of a.
Click here to see answer by jim_thompson5910(28476)

Question 118664: explain why a^0 =1 for any nonzero value of a.
Click here to see answer by scott8148(6628)

Question 118443: What is the transformational form of y= -1/3x^2+3x-1 ?
I got -3(y+23/4) =(x+9/2)^2 It was marked wrong :(
Click here to see answer by MathLover1(6611)

Question 118550: sketch the graph of the function. label the coordinates of the vertex. make sure to make your x & y table. then plot the points on the graph.
1) y=-x^2-4x+2

solve the equation algebraically. check your solution by graphing. make sure to use an x &y table.
2)x^2-4=12
Click here to see answer by ankor@dixie-net.com(15622)

Question 118578: 2B(3-B?)/B^2-9
Click here to see answer by MathLover1(6611)

Question 118719:
A right-angled triangle has a perimeter of 120cm. If the hypoteneuse is 50cm, find the length of the other two sides.
Click here to see answer by checkley71(8403)

Question 118718: A square swimming pool with a side measuring 16m is to be surrounded with a uniform rubberized floor covering of width x. If the area of the floor covering equals the area of the pool, find the width of the rubberized covering.
Click here to see answer by checkley71(8403)

Question 118736: Please help to solve this problem. 3x^2 + x - 0 =
Thanking you
Click here to see answer by jim_thompson5910(28476)

Question 118752: Please help with this problem 3x^2 + x -4 = 0 What is the solution set ?
Thank you
Click here to see answer by jim_thompson5910(28476)

Question 118762: Please help me to solve this equation
3x^2 - 2x = 15x - 10
Click here to see answer by ilana(307)

Question 118762: Please help me to solve this equation
3x^2 - 2x = 15x - 10
Click here to see answer by MathLover1(6611)

Question 118765: Find the root(s) of x-2/x-4 + 2= 2x+3/5
Can someone please tell me why I lost marks :(
I Did : 5(x-2)+2(x-4)=(2x+3)(x-4)
5x-10+2x-8=2x^2-8x+3x-12
7x-18=2x62-5x-12
7x-18+-2x^2+5x+12=0
12x-6+-2x^2=0
x^2+-6x+3=0
Then I used the quadratic formula and got:
x=6+-2sqrt6/2
x=3=-sqrt6

Click here to see answer by jim_thompson5910(28476)

Question 118768:
A picture measuring 40cm by 60cm is surrounded by a frame of uniform width. If the area of the frame equals the area of the picture,then what is the width of the frame ?
Please help me :)
Click here to see answer by checkley71(8403)

Question 118779: I have no text book. I stand on a building, 96 feet high. I throw a ball upward at an initial velocity of 80 feet per second. How long will it take for the ball to reach me and how long will it take for the ball to reach the ground?
Click here to see answer by ankor@dixie-net.com(15622)

Question 118818: What is the discriminant of (3x+2)x=4-2x? I think the answer is 64 but I need an explaination . Please help me :)
Click here to see answer by ilana(307)

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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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