Questions on Algebra: Equations answered by real tutors!

Tutors Answer Your Questions about Equations (FREE)

Question 1184554: The value of c in the standard form of the equation 2a² + 4a - 40 = - 10
Click here to see answer by josgarithmetic(39616)

Question 1184553: the value of b in the standard form of the equation 4x² = 28x = - 19 + 5x. please help me answer this question, thank you very much<3

Click here to see answer by josgarithmetic(39616)

Question 1184565: The function x^(2)e^(−4x) is annihilated by the operator
Click here to see answer by ikleyn(52776)

Question 1184565: The function x^(2)e^(−4x) is annihilated by the operator
Click here to see answer by robertb(5830)

Question 1184582: What are the solution of the quadratic equation? (3x - 7)² = 25
Click here to see answer by josgarithmetic(39616)

Question 1184587: The value of a in the standard form of the equation (x + 7)² - 6 = 5°
Click here to see answer by ankor@dixie-net.com(22740)

Question 1184587: The value of a in the standard form of the equation (x + 7)² - 6 = 5°
Click here to see answer by ikleyn(52776)

Question 1184587: The value of a in the standard form of the equation (x + 7)² - 6 = 5°
Click here to see answer by josgarithmetic(39616)

Question 1184587: The value of a in the standard form of the equation (x + 7)² - 6 = 5°
Click here to see answer by greenestamps(13198)

Question 1184581: What is the value of c in the standard form of the equation -2(3x-1)(3x+1)=0?
Click here to see answer by josgarithmetic(39616)

Question 1184581: What is the value of c in the standard form of the equation -2(3x-1)(3x+1)=0?
Click here to see answer by ikleyn(52776)

Question 1184581: What is the value of c in the standard form of the equation -2(3x-1)(3x+1)=0?
Click here to see answer by greenestamps(13198)

Question 1184580: What is the value of a in the standard form of the equation -x² +6x + 18 = 0?
Click here to see answer by josgarithmetic(39616)

Question 1184580: What is the value of a in the standard form of the equation -x² +6x + 18 = 0?
Click here to see answer by ikleyn(52776)

Question 1184614: Create an equation that requires the use of the addition property of equality, where 1/2 must be subtracted from each side and the solution is a positive number.
Click here to see answer by Edwin McCravy(20054)

Question 1184652: An object with mass 21kg is in free fall. It has two forces acting on it: gravity and air resistance. For this model we will take the ground to be at height 0, the height of the object to be y(t) meters from the ground, and the acceleration due to gravity to be −9.81ms^(2).
We want to set up a differential equation for the forces acting on the object. The force due to gravity is is given by mass times acceleration acting in the opposite direction of y. The force due to air resistance is proportional to the square root of the velocity of the object in the same direction is y. The constant of proportionality for the wind resistance has been measured at 0.55. Find the differential equation that models the displacement of the object y at time t.
My answer is -9.81+(0.55/21)sqrt(y')=0 , wrong.
Click here to see answer by ikleyn(52776)

Question 1184644: Solve the initial-value problem d^(2)y/dt^(2)+4dy/dt+4y=0,y(1)=0,y′(1)=1.
y(t)=
Click here to see answer by robertb(5830)

Question 1184638: For this problem you may want to recall that if y=sinh(x), then dy/dx=cosh(x), and d^(2)y/dx^(2)=sinh(x).
It can be shown that y1=sinh(3x), y2=cosh(3x) and y3=e^(3x) are solutions to the differential equation xD^(3)y−8D^(2)y−9xDy+72y=0 on (0,∞).
a)
What does the Wronskian of y1,y2,y3 equal on (0,∞)?
W(y1,y2,y3)=______________________ on (0,∞).
b)
Is {y1,y2,y3} a fundamental set for xD^(3)y−8D^(2)y−9xDy+72y=0 on (0,∞)?
Yes or No
Click here to see answer by robertb(5830)

Question 1184695: You measure 41 textbooks' weights, and find they have a mean weight of 49 ounces. Assume the population standard deviation is 12.6 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight.
Give your answers as decimals, to two places
I am 95% confident that the mean weight of textbooks is between____
and ______ ounces.

Click here to see answer by robertb(5830)

Question 1184722: what is the value of a in the standard form of the equation (2x+3)(3x - 2) = 0?
Click here to see answer by ikleyn(52776)

Question 1184725: II- Translating verbal sentences into mathematical expression
1. The sum of two integers is 76 and their difference is 2. What are the integers?

Click here to see answer by josgarithmetic(39616)

Question 1184738: Can these be factored using the methods (GCF, squares, cubes)
a4 + 1
a4 - 64
Click here to see answer by ikleyn(52776)

Question 1184745: make t the subject of formula x=t(1-t
^2)/11+t^2
Click here to see answer by greenestamps(13198)

Question 1184758: two trains leave the station at the same time, one heading east and the other west. The eastbound train travels at 75 miles per hour. The westbound train travels at 95 mph. how long will it take for the two trains to be 442 miles apart? Don't do any rounding.
Click here to see answer by ikleyn(52776)

Question 1184759: for each ordered pair, determine whether it is a solution to the system of equations.
{12x+3y=9
y=-4x+3}
Is it a solution?
(1,5)
(0,-7)
(3,-9)
(-2,11)

Click here to see answer by ikleyn(52776)

Question 1184760: Yoko deposits $2000 into an account that pays simple interest at a rate of 5% per year. how much interest will she be paid in the first 5 years?
Click here to see answer by ikleyn(52776)

Question 1184761: The sets G and B are given below.
g={1,5,7,8}
b={-2,4,7}
find the intersection of g and b
find the union of G and B
write answers in set notation.
Click here to see answer by MathLover1(20849)

Question 1184692: Out of 600 people sampled, 540 had kids. Based on this, construct a 99% confidence interval for the true population proportion of people with kids.
Give your answers as decimals, to three places
I am 99% confident that the proportion of people who have kids is between_____
and_____.

Click here to see answer by Edwin McCravy(20054)

Question 1184913: Greatest common factor?
24xy^3+42xy^2+54x^4y^4
Click here to see answer by greenestamps(13198)

Question 1184846: A researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 30 bacteria reveals a sample mean of
¯
x
=
80
hours with a standard deviation of
s
=
4.2
hours. He would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.45 hours at a 90% level of confidence.
What sample size should you gather to achieve a 0.45 hour margin of error?
He would need to sample_____ bacteria.
Click here to see answer by Boreal(15235)

Question 1184950: The unit digit of a two digit number is 1 less than the tens digit. If the number is increased by 8 and then divided by the sum of the digits, the result is 8. Find the number.
Click here to see answer by ikleyn(52776)

Question 1185080: Hi there, here's my question.
Bill works half as many hours per week as Phil. Between the two, they work a total
of 48 hours in one week. How many hours did both work?
Please solve using two variables.
Thanks!
Click here to see answer by josgarithmetic(39616)

Question 1185081: The Clarks will be leaving on a road trip. One car rental place charges $180 for a
week and 41 cents per km. Another car rental place charges $275 for the week and 21
cents per km. Find the distance where both places charge the same amount.
Thank you!
Click here to see answer by josgarithmetic(39616)

Question 1185184: Given (3y, 2x - 3) = (-9, -7)
a) Find x and y
b) Find 3x - 2y
Can you please help me with this homework question?
Click here to see answer by MathLover1(20849)

Question 1185188: Derive step by step the differential equation of the brachistochron curve
Click here to see answer by ikleyn(52776)

Question 1185189: Solve the differential equation that models the brachistochron curve. (If you are going to use one or more variable changes, you must justify by reasoning why these variable changes can be used).
Click here to see answer by ikleyn(52776)

Question 1185206: A student has test grades of 91,86 and 85,what must be her next test grade in order to have a 90 average
Click here to see answer by Alan3354(69443)

Question 1185206: A student has test grades of 91,86 and 85,what must be her next test grade in order to have a 90 average
Click here to see answer by greenestamps(13198)

Question 1185219: Express the column matrix b as a linear combination of the columns of A. (Use A1, A2, and A3 respectively for the columns of A.)
A =
3 1 2
1 −1 −3
,
b = −1
3

Click here to see answer by greenestamps(13198)

Question 1185218: Find, if possible, AB and BA. (If not possible, enter IMPOSSIBLE in any single
cell.)

Click here to see answer by Edwin McCravy(20054)

Question 1185271: (-4,6) across the x axis
Click here to see answer by math_helper(2461)

Question 1185426: A convertible and a minivan leave a highway junction At the same time. The convertible travels west at 75 miles per hour and the minivan travels north 65 per hour. Assuming the two vehicles do not deviate course how far apart are they after 3 hours?
Click here to see answer by ikleyn(52776)

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, 30241..30285, 30286..30330, 30331..30375, 30376..30420, 30421..30465, 30466..30510, 30511..30555, 30556..30600, 30601..30645, 30646..30690, 30691..30735, 30736..30780, 30781..30825, 30826..30870, 30871..30915, 30916..30960, 30961..31005, 31006..31050, 31051..31095, 31096..31140, 31141..31185, 31186..31230, 31231..31275, 31276..31320, 31321..31365, 31366..31410, 31411..31455, 31456..31500, 31501..31545, 31546..31590, 31591..31635, 31636..31680, 31681..31725, 31726..31770, 31771..31815, 31816..31860, 31861..31905, 31906..31950, 31951..31995, 31996..32040, 32041..32085, 32086..32130, 32131..32175, 32176..32220, 32221..32265, 32266..32310, 32311..32355, 32356..32400, 32401..32445, 32446..32490, 32491..32535, 32536..32580, 32581..32625, 32626..32670, 32671..32715, 32716..32760, 32761..32805, 32806..32850, 32851..32895, 32896..32940, 32941..32985, 32986..33030, 33031..33075, 33076..33120, 33121..33165, 33166..33210, 33211..33255, 33256..33300, 33301..33345, 33346..33390, 33391..33435, 33436..33480, 33481..33525, 33526..33570, 33571..33615, 33616..33660, 33661..33705, 33706..33750, 33751..33795, 33796..33840, 33841..33885, 33886..33930, 33931..33975, 33976..34020, 34021..34065, 34066..34110, 34111..34155, 34156..34200, 34201..34245, 34246..34290, 34291..34335, 34336..34380, 34381..34425, 34426..34470, 34471..34515, 34516..34560, 34561..34605, 34606..34650, 34651..34695, 34696..34740, 34741..34785, 34786..34830, 34831..34875, 34876..34920, 34921..34965, 34966..35010, 35011..35055, 35056..35100, 35101..35145, 35146..35190, 35191..35235, 35236..35280, 35281..35325, 35326..35370, 35371..35415, 35416..35460, 35461..35505, 35506..35550, 35551..35595, 35596..35640, 35641..35685, 35686..35730, 35731..35775, 35776..35820, 35821..35865, 35866..35910, 35911..35955, 35956..36000, 36001..36045, 36046..36090, 36091..36135, 36136..36180, 36181..36225, 36226..36270, 36271..36315, 36316..36360, 36361..36405, 36406..36450, 36451..36495, 36496..36540, 36541..36585, 36586..36630, 36631..36675, 36676..36720, 36721..36765, 36766..36810, 36811..36855, 36856..36900, 36901..36945, 36946..36990, 36991..37035, 37036..37080, 37081..37125, 37126..37170, 37171..37215, 37216..37260, 37261..37305, 37306..37350, 37351..37395, 37396..37440, 37441..37485, 37486..37530, 37531..37575, 37576..37620, 37621..37665, 37666..37710, 37711..37755, 37756..37800, 37801..37845, 37846..37890, 37891..37935, 37936..37980, 37981..38025, 38026..38070, 38071..38115, 38116..38160, 38161..38205, 38206..38250, 38251..38295, 38296..38340, 38341..38385, 38386..38430, 38431..38475, 38476..38520, 38521..38565, 38566..38610, 38611..38655, 38656..38700, 38701..38745, 38746..38790, 38791..38835, 38836..38880, 38881..38925, 38926..38970, 38971..39015, 39016..39060, 39061..39105, 39106..39150, 39151..39195, 39196..39240, 39241..39285, 39286..39330, 39331..39375, 39376..39420, 39421..39465, 39466..39510, 39511..39555, 39556..39600, 39601..39645, 39646..39690, 39691..39735, 39736..39780, 39781..39825, 39826..39870, 39871..39915, 39916..39960, 39961..40005, 40006..40050, 40051..40095, 40096..40140, 40141..40185, 40186..40230, 40231..40275, 40276..40320, 40321..40365, 40366..40410, 40411..40455, 40456..40500, 40501..40545, 40546..40590, 40591..40635, 40636..40680, 40681..40725, 40726..40770, 40771..40815, 40816..40860, 40861..40905, 40906..40950, 40951..40995, 40996..41040, 41041..41085, 41086..41130, 41131..41175, 41176..41220, 41221..41265, 41266..41310, 41311..41355, 41356..41400, 41401..41445, 41446..41490, 41491..41535, 41536..41580