Questions on Algebra: Quadratic Equation answered by real tutors!

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Question 83834: Calculate the indicated value.
f(x) = 7x - 27x^2 - 7
find f(-7)
I'm not sure where to start, do I just replace each x with -7? I have a few question like this and if possible I'd like to see the steps and the answer so I can figure out the rest of my questions. Thank you for your help!
Click here to see answer by jim_thompson5910(35256)

Question 83818: A ball is thrown upward from the roof of a building 100 m tall with an initial velocity of 20 m/s. When will the ball reach a height of 80 m?
Click here to see answer by ankor@dixie-net.com(22740)

Question 83889: If the sides of a square are decreased by 2cm, the area is decreased by 36cm^2. What are the dimensions of the original square?

Click here to see answer by stanbon(75887)

Question 83835: the sum of the solutions of 3x^+3x=36
Click here to see answer by Nate(3500)

Question 83899: How do you find a quadratic function to model the values in the table? Predict the value of y for x=6.
x y
-1 -2
0 4
3 -26
Could you also help me with finding a quadratic model for th set of values.
(-2,19)(0,3)(4,19) Thanks alot. Forgot all these things that we did at the beginning of the year.
Click here to see answer by Nate(3500)

Question 83904: Find the distance between each pair of points (-3,0) and (4,0)
Click here to see answer by Nate(3500)

Question 83933: Factor completely. 3(x � 2)^2 � 3(x � 2) � 6
Click here to see answer by Edwin McCravy(20054)

Question 83944: how do you solve quadratic equations and then also simplify the radical solution???
examle: 5(x.squared)- (x.squared)=42

help!!!
Click here to see answer by bucky(2189)

Question 83931: Factor completely. 6x^2 + 7x + 2
Click here to see answer by jim_thompson5910(35256)

Question 83932: Factor. 8m^4n � 16mn^4
Click here to see answer by checkley75(3666)

Question 83930: Write using positive exponents only. b^�2
Click here to see answer by tutor_paul(519)

Question 83930: Write using positive exponents only. b^�2
Click here to see answer by checkley75(3666)

Question 83917: Would someone show me step by step how to figure this problem. Please. Thank You.
The profit on a watch is given by P=x^2-13x-80, where x is the number of watches sold per day. How many watches were sold on a day when there was a $50 loss?
Click here to see answer by jim_thompson5910(35256)

Question 83928: Simplify. (m^5)^8
Click here to see answer by checkley75(3666)

Question 83926: Multiply. (x + 2)(x � 2)
Click here to see answer by checkley75(3666)

Question 83968: Factor. 9x(x � 7y) � 6(x � 7y)
Click here to see answer by Nate(3500)

Question 83971: Solve: x^2 + 4x � 12 = 0
Click here to see answer by Nate(3500)

Question 83974: Factor completely. 18x^3 � 36x^2
Click here to see answer by Nate(3500)

Question 83973: Factor by grouping. x^3 � 3x^2 + 4x � 12
Click here to see answer by Nate(3500)

Question 83970: Factor completely. ax � ay + x^2 � xy
Click here to see answer by Nate(3500)

Question 83969: Rewrite the middle term as the sum of two terms and then factor completely.
15x^2 � 21x + 6

Click here to see answer by Nate(3500)

Question 83923: Subtract 5m2 + 2m + 9 from 7m2 � 5m � 8.

Click here to see answer by tutor_paul(519)

Question 83821: The demand equation for a certain type of printer is given by D=-200p+35,500. The supply equation is predicted to be S=-p^2+400p-20,000. Find the equilibrium price.
Click here to see answer by ankor@dixie-net.com(22740)

Question 83987: Write using positive exponents, and simplify if possible.
(�3x)^�2

Click here to see answer by tutorcecilia(2152)

Question 83985: Simplify. (m^4)^3(m^2)^9/(m^3)^2
Click here to see answer by tutorcecilia(2152)

Question 83983: Multiply. 3xy^2(5xy � 4x + 6y)

Click here to see answer by tutorcecilia(2152)

Question 83922: Multiply. (3x � 1)(2x + 5)
Click here to see answer by ankor@dixie-net.com(22740)

Question 83981: Rewrite the middle term as the sum of two terms and then factor by grouping.
x^2 � 2x � 63

Click here to see answer by stanbon(75887)

Question 83986: Multiply. Write the answer in scientific notation.
(2.4 x 10^�5)(4 x 10^�4)

Click here to see answer by stanbon(75887)

Question 83982: Write 9.03 x 10^�2 in standard notation
Click here to see answer by stanbon(75887)

Question 84001: Find the x-intercepts. y=x^2-4x+4.
Click here to see answer by scott8148(6628)

Question 84031: What is the vertex form of y=(3x+1)(x-2)and y=3(x-2)?
Is it y=3(x-5/6)^2-4.03?
Click here to see answer by vertciel(183)

Question 84031: What is the vertex form of y=(3x+1)(x-2)and y=3(x-2)?
Is it y=3(x-5/6)^2-4.03?
Click here to see answer by Edwin McCravy(20054)

Question 84003: Find the x-intercepts. y=x^2-2x+4
Click here to see answer by checkley75(3666)

Question 83967: Rewrite the middle term as the sum of two terms and then factor by grouping.
x^2 � 2x � 63

Click here to see answer by praseenakos@yahoo.com(507)

Question 84000: Solve by completing the square. 4x^2+2x-3=0
Click here to see answer by tanimachatterjee(60)

Question 84020: When using the quadratic formula to solve a quadratic equation (ax2 + bx + c = 0), the discriminant is b2 - 4ac. This discriminant can be positive, zero, or negative.
Create three unique equations where the discriminant is positive, zero, or negative. For each case, explain what this value means to the graph of y = ax2 + bx + c.

Click here to see answer by rapaljer(4671)

Question 83966: Multiply. 3xy^2(5xy � 4x + 6y)
Click here to see answer by tutor_paul(519)

Question 84116:
Determine the number of solutions and tell if the discriminant is greater than 0, equal to 0 or less than 0. Select two answers.

Click here to see answer by funmath(2933)

Question 84185: My professor says that the following word problem can be solved using a form of the quadratic equation. I can't see it, and all my attempts to solve via trial and error have failed. Please explain how this works!
"Find two numbers whose sum is 6 and whose product is 2"
Thanks,
para.lax
Click here to see answer by checkley75(3666)

Question 84177: I can't figure out how to divide this problem. The problem is;
x^3+2x^2+x+12 divided by x+3
Click here to see answer by vertciel(183)

Question 82805: (2X-6)^2=-8
Click here to see answer by vertciel(183)

Question 84190: I am supposed to set up a quadratic equation for this word problem, but I don't see how to do that. The problem is:
Working alone, Colleen can paint a house in 2 hours less than James. Working together, they can paint the house in 10 hours. how long would it take James to pain the house by himself.
Click here to see answer by ankor@dixie-net.com(22740)

Question 81348: Solve the following system by addition. If a unique solution does not exist, state whether the system is inconsistent or dependent.
x+5y=10
-2x-10y=-20
Click here to see answer by vertciel(183)

Question 84333: What is the process to write the Quadratic equation that goes through the points (0,12),(4,0) and(-3,0)
Click here to see answer by funmath(2933)

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