Questions on Algebra: Expressions involving variables, substitution answered by real tutors!

Tutors Answer Your Questions about Expressions-with-variables (FREE)

Question 309853: Commuting students. At a well-known university,
¼ of the undergraduate students commute, and 1/3 of the graduate students commute. One-tenth of the undergraduate students drive more than 40 miles daily, and 1/6 of the graduate students drive more than 40 miles daily. If there are twice as many undergraduate students as there are graduate
students, then what fraction of the commuters drive more
than 40 miles daily?

Click here to see answer by ankor@dixie-net.com(15646)

Question 310627: the ratio of 9 more than m to m
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Question 310639:
Click here to see answer by PRMath(123)

Question 310650: translate the following into a variable expression 6 divided by the difference between x and 4
Click here to see answer by Fombitz(13828)

Question 310649: When is the rational expression 1/(s+y) undefined? x=? s=?
Click here to see answer by unlockmath(1599)

Question 310649: When is the rational expression 1/(s+y) undefined? x=? s=?
Click here to see answer by Fombitz(13828)

Question 310648: When is the rational expression x/2y equal to 0?
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Question 310638: Evaluate the variable expression when a = 7, b = –2, and c = 5.
2b - (2c+a²)
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Question 310640: 5x+4x
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Question 310735: Solve for x.

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Question 310738: Solve by substitution method. Thank you.
7m+n=49
m-3n=29
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Question 310637: Evaluate the variable expression when a = 6 and b = 1.
5a − 6b
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Question 310771: (7x^5y^9z^13)^(1/5) simplify

Click here to see answer by stanbon(57290)

Question 310704: how many millimeters of a 40 percent acid solutionn and how many of a 10 percent acid solution must be mixed together to produice 30 millimeters 20 percents solution
Click here to see answer by checkley77(12569)

Question 310651: -6/7(287-56)
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Question 310860: How can you solve for x? -12= -8 -2x

Thanx in advance!
Click here to see answer by stanbon(57290)

Question 311015: 6d^2/4c divide by c^2d^3/18
Click here to see answer by Fombitz(13828)

Question 311222: (xyz+2x)(xz-10x)
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Question 311182: I really need help with the steps to this equation, I really dont know what I'm doing and would really like to learn before my exam on monday. this is the problem:solving inconsistent systems and dependent systems/ 3x - y =7
14x + 6 =2y

Click here to see answer by mananth(12270)

Question 311261: 3x+(-8y)-10x+4x
Click here to see answer by rfer(12655)

Question 311365: i really need help with this problem because I can't figure out what the LCD is.
Add or subtract as indicated 7b+6/6b-36 - b+2/b-6
The answer is 1/?
Click here to see answer by JBarnum(2044)

Question 312191: evaluate the expression 70x2 50-30

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Question 312238: decompose the expression (17n-23)/ (4n^2+23n-6) into partial fractions
Click here to see answer by solver91311(16877)

Question 312234: decompose the expression (17n-23)/(4n^2+23n-6) into partial fractions.
Click here to see answer by solver91311(16877)

Question 312392: Suppose the table below shows the number of living kidney donors for a certain year, by age. What percent of the donors are aged 35-49? Round to the nearest tenth of a percent.

Ages- Donors
18-34 2177
35-39 2811
50-64 1292
65+ 52

Click here to see answer by OmniMaestra(21)

Question 312390: 45 is _____% of 25.
Click here to see answer by nyc_function(2733)

Question 312389: -4=5/9t
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Question 312522: 5x+2y=-7
7x-3y=17
How do I find what to multiple them by each time to help solve the system by the elimination method?
Click here to see answer by Fombitz(13828)

Question 312393: Palmer's average running speed is 3 kilometers per hour faster than his walking speed. If Palmer can run around a 30-kilometer course in 4 hours, how many hours would it take for Palmer to walk the same course? (Round your answer to two decimal places.)
Click here to see answer by Fombitz(13828)

Question 312659: I am confused on the following problem:
During a 3000 mi flight, a plance encountered a strong tail wind that increased its speed by 100 mi/h. This increase in speed shortened the flying time by one hour. Find the speed of the plane relative to the ground.
Click here to see answer by mananth(12270)

Question 312650: perform the operations: 3/x2-x - 2x-1/x2+2x-3
Click here to see answer by Fombitz(13828)

Question 312768: I bought my two children each a winter coat just a few months ago for next year while they were on clearance. My sons jacket was originally priced at $74.99 with 25% off and my daughters jacket was originally priced at $69.99 with 20% off. What was the total for each jacket after the discount.
Click here to see answer by nerdybill(6957)

Question 312767: I bought a furniture set for 1600 in the month of april and just recently saw an add for the same set on sale for 20%off. Had I waited a couple of months to purchase it how much would I have saved?
Click here to see answer by nerdybill(6957)

Question 313617: x+y=56, 3x+y=56, how do I solve this by substition? Please Help
Click here to see answer by OmniMaestra(21)

Question 313805: A certain country's population P(t), in millions, t years after 1980 can be approximated by
P(t) = 5.495(1.016)t .
In what year did the country's population reach 3 million?
a.1947
b.1932
c.1942
d.1952
I can't do it backwards. Please help
Click here to see answer by nerdybill(6957)

Question 314116: One eighth of a number is four.
Find the number
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Question 314115: A piece of ribbon 7 feet long is cut into two pieces, one shorter than the other. Let L denote the length of the longer piece. Express the length of the shorter piece of ribbon in terms of L.
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Question 314114: Translate into a variable expression and then simplify.
the product of seven times a number and eight
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Question 314113: Translate into a variable expression and then simplify.
the sum of twelve times a number and the product of seven and the number
Click here to see answer by rapaljer(4667)

Question 314112: Translate into a variable expression.
Four times the sum of 4 and x
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Question 314215: Hi, can you please help me with this?

Click here to see answer by Fombitz(13828)

Question 314336: Please help! I have to get this done.
Simplify (if possible).
a) I was having trouble getting this one to display the right way so I just typed it out normally. I hope you can still understand it.
2x/2x^2-7x+3 - x/x^2-9
b)
Click here to see answer by Jstrasner(106)

Question 314371: Hi, I need help on this one. I have to solve it.
(for )
Click here to see answer by rapaljer(4667)

Question 314371: Hi, I need help on this one. I have to solve it.
(for )
Click here to see answer by checkley77(12569)

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