# See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On

 Tutoring Home For Students Tools for Tutors Our Tutors Register Recently Solved
 By Tutor
| By Problem Number |

Tutor:

# Recent problems solved by 'rfer'

rfer answered: 12656 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589 , 7590..7619 , 7620..7649 , 7650..7679 , 7680..7709 , 7710..7739 , 7740..7769 , 7770..7799 , 7800..7829 , 7830..7859 , 7860..7889 , 7890..7919 , 7920..7949 , 7950..7979 , 7980..8009 , 8010..8039 , 8040..8069 , 8070..8099 , 8100..8129 , 8130..8159 , 8160..8189 , 8190..8219 , 8220..8249 , 8250..8279 , 8280..8309 , 8310..8339 , 8340..8369 , 8370..8399 , 8400..8429 , 8430..8459 , 8460..8489 , 8490..8519 , 8520..8549 , 8550..8579 , 8580..8609 , 8610..8639 , 8640..8669 , 8670..8699 , 8700..8729 , 8730..8759 , 8760..8789 , 8790..8819 , 8820..8849 , 8850..8879 , 8880..8909 , 8910..8939 , 8940..8969 , 8970..8999 , 9000..9029 , 9030..9059 , 9060..9089 , 9090..9119 , 9120..9149 , 9150..9179 , 9180..9209 , 9210..9239 , 9240..9269 , 9270..9299 , 9300..9329 , 9330..9359 , 9360..9389 , 9390..9419 , 9420..9449 , 9450..9479 , 9480..9509 , 9510..9539 , 9540..9569 , 9570..9599 , 9600..9629 , 9630..9659 , 9660..9689 , 9690..9719 , 9720..9749 , 9750..9779 , 9780..9809 , 9810..9839 , 9840..9869 , 9870..9899 , 9900..9929 , 9930..9959 , 9960..9989 , 9990..10019 , 10020..10049 , 10050..10079 , 10080..10109 , 10110..10139 , 10140..10169 , 10170..10199 , 10200..10229 , 10230..10259 , 10260..10289 , 10290..10319 , 10320..10349 , 10350..10379 , 10380..10409 , 10410..10439 , 10440..10469 , 10470..10499 , 10500..10529 , 10530..10559 , 10560..10589 , 10590..10619 , 10620..10649 , 10650..10679 , 10680..10709 , 10710..10739 , 10740..10769 , 10770..10799 , 10800..10829 , 10830..10859 , 10860..10889 , 10890..10919 , 10920..10949 , 10950..10979 , 10980..11009 , 11010..11039 , 11040..11069 , 11070..11099 , 11100..11129 , 11130..11159 , 11160..11189 , 11190..11219 , 11220..11249 , 11250..11279 , 11280..11309 , 11310..11339 , 11340..11369 , 11370..11399 , 11400..11429 , 11430..11459 , 11460..11489 , 11490..11519 , 11520..11549 , 11550..11579 , 11580..11609 , 11610..11639 , 11640..11669 , 11670..11699 , 11700..11729 , 11730..11759 , 11760..11789 , 11790..11819 , 11820..11849 , 11850..11879 , 11880..11909 , 11910..11939 , 11940..11969 , 11970..11999 , 12000..12029 , 12030..12059 , 12060..12089 , 12090..12119 , 12120..12149 , 12150..12179 , 12180..12209 , 12210..12239 , 12240..12269 , 12270..12299 , 12300..12329 , 12330..12359 , 12360..12389 , 12390..12419 , 12420..12449 , 12450..12479 , 12480..12509 , 12510..12539 , 12540..12569 , 12570..12599 , 12600..12629 , 12630..12659, >>Next

 Mixture_Word_Problems/325039: a man orders 60 pounds of cashews and peanuts, if he orders 24 pounds less of cashews, how many pounds of peanuts was ordered?1 solutions Answer 232802 by rfer(12660)   on 2010-07-23 20:46:12 (Show Source): You can put this solution on YOUR website!x+x-24=60 2x=84 x=42 x-24=18
 Average/325095: His test scores were 80, 88, 71, and 75. After his next test he found his average to be 78. What did he score on his fifth exam?1 solutions Answer 232799 by rfer(12660)   on 2010-07-23 20:42:02 (Show Source): You can put this solution on YOUR website!(80+88+71+75+x)/5=78 313+x/5=78 313+x=390 x=77
 Permutations/325078: If 1.5 chickens lay 1.5 eggs in 1.5 days, how many eggs do 9 chickens lay in 15 days?1 solutions Answer 232784 by rfer(12660)   on 2010-07-23 18:56:46 (Show Source): You can put this solution on YOUR website!15*9=135
 Linear-equations/325068: How many solutions exist for the following system of equations? -4x – 6y = -28 2x + 3y = 14 And do you know how to enter these type of equations on a graphing calculator? More specific, a TI-84 Plus?1 solutions Answer 232781 by rfer(12660)   on 2010-07-23 18:14:53 (Show Source): You can put this solution on YOUR website!Enter both equations in the calculator, graph both the intersections of the two are the solution. Refer to web site TI-84 Silver Edition Calculator atomiclearning.com
 Money_Word_Problems/325051: \$20,000 is invested at 16% per year for 3 months. How much interest is earned on the investment? I've tried 16% divided by 12 = 1 4/12 *3 = 2 1/3 is that right?1 solutions Answer 232779 by rfer(12660)   on 2010-07-23 18:06:54 (Show Source): You can put this solution on YOUR website!A=20000(1+.16/12)^3 A=20000(1+0.01333)^3 A=20000*1.04 A=20800 20800-20000=\$800
 Geometric_formulas/324954: what is the length and width of an object that has a perimeter of 42 inches if the width is 5 inches more than the length?1 solutions Answer 232763 by rfer(12660)   on 2010-07-23 16:44:15 (Show Source): You can put this solution on YOUR website!2x+2(x+5)=42 4x+10=42 4x=32 x=8 x+5=13
 Travel_Word_Problems/324980: Dan and Kathy are both traveling south for spring break. Dan is taking a bus traveling at 60mph and Kathy is driving her own car at 70mph. If Dan passes Jacksonville at 2:00pm and Kathy passes through Jacksonville at 2:30pm what time will Kathy catch up to Dan?1 solutions Answer 232762 by rfer(12660)   on 2010-07-23 16:41:01 (Show Source): You can put this solution on YOUR website!dan has 30 mi lead overtake at 10 mph 30/10=3 hrs 2:30+3=5:30 pm
 Equations/324852: v-4(4-v)=-2(2v-1)1 solutions Answer 232580 by rfer(12660)   on 2010-07-22 20:16:36 (Show Source): You can put this solution on YOUR website!v-16+4v=-4v+2 9v=18 v=2
 Square-cubic-other-roots/324810: if you have a number above the check mark part of the square root what is it called? i am looking for lessons on it but dont know what to look up to find info on it. thanks1 solutions Answer 232556 by rfer(12660)   on 2010-07-22 19:11:32 (Show Source): You can put this solution on YOUR website!You are referring to the index
 Sequences-and-series/324829: What is next in this sequence and how do I solve probems like this, is there a formula? 1 5 14 30 55 91 1401 solutions Answer 232554 by rfer(12660)   on 2010-07-22 19:04:55 (Show Source): You can put this solution on YOUR website!204 is next ------------- 1 5 14 30 55 91 140 204 4 9 16 25 36 49 64 5 7 9 11 13 15 2 2 2 2 2
 Quadratic_Equations/324725: 5x(x - 1) - 7 = 4x(x -2)1 solutions Answer 232526 by rfer(12660)   on 2010-07-22 16:40:29 (Show Source): You can put this solution on YOUR website!5x^2-5x-7=4x^2-8x x^2+3x-7=0
 Rectangles/324756: Draw a rectangle with a perimeter of 20 inches label its sides.1 solutions Answer 232525 by rfer(12660)   on 2010-07-22 16:38:06 (Show Source): You can put this solution on YOUR website!a square with 5 in on each side
 test/324794: simplify 2a + 3b - a 1 solutions Answer 232524 by rfer(12660)   on 2010-07-22 16:36:55 (Show Source): You can put this solution on YOUR website!a+3b
 Volume/324791: The volume of a cylinder is 1017.88 inches cubed. The radius is 6 inches. WHat is the height?1 solutions Answer 232522 by rfer(12660)   on 2010-07-22 16:36:30 (Show Source): You can put this solution on YOUR website!1017.88/3.14*6=h 1017.88/18.84=53.98 in
 Expressions-with-variables/324793: Simplify 1.3a + 2b (4b + 3.1a) - 4a1 solutions Answer 232519 by rfer(12660)   on 2010-07-22 16:34:24 (Show Source): You can put this solution on YOUR website!1.3a+8b^2+6.2ab-4a +8b^2+6.2ab-2.7a
 test/324792: simplify (4x + 3y) - (2x -5y)1 solutions Answer 232518 by rfer(12660)   on 2010-07-22 16:31:26 (Show Source): You can put this solution on YOUR website!4x+3y-2x+5y 2x+8y
 Graphs/324627: Graph the inequality 2x+4+3x<8+3x+61 solutions Answer 232506 by rfer(12660)   on 2010-07-22 16:06:59 (Show Source): You can put this solution on YOUR website!2x<10 x<5 circle around 5 with arrow pointing to the left
 Polynomials-and-rational-expressions/324772: a^2-2-35 with a =11 solutions Answer 232504 by rfer(12660)   on 2010-07-22 16:02:10 (Show Source): You can put this solution on YOUR website!a^2-2-35 1^2-2-35 1-2-35=36
 Miscellaneous_Word_Problems/324757: a student finishes the first half of an exam in 2/3 the time it takes him to finish the second half. if the entire takes him an hour, how many minutes does he spend on the first half of the exam1 solutions Answer 232501 by rfer(12660)   on 2010-07-22 16:00:28 (Show Source): You can put this solution on YOUR website!40 min
 percentage/324771: I am taking a practice test. One of my questions is: "A rancher is planning to put up 220 yards of fencing. In the morning, she puts up 80 yards of fencing. In the afternoon she puts up 40% of the remaining fence. What is the total percentage of the amount of fencing she has put up today?" I know the answer is 62%. Every time i work out the answer however, i get 76%. How do you work this problem out?1 solutions Answer 232498 by rfer(12660)   on 2010-07-22 15:54:58 (Show Source): You can put this solution on YOUR website!220-80=140 140*.4=56 80+56=136 136/220=0.618or rounded to 62%
 Polynomials-and-rational-expressions/324688: Simplify (1/2)^2 and (1/2)^-2 Thank you1 solutions Answer 232455 by rfer(12660)   on 2010-07-22 13:26:18 (Show Source): You can put this solution on YOUR website!a 1/4 b 4
 Polynomials-and-rational-expressions/324737: Simplify 1/z-1 - 1/z+11 solutions Answer 232452 by rfer(12660)   on 2010-07-22 13:23:09 (Show Source): You can put this solution on YOUR website!looks like 0
 Exponents/324658: I am new at this so here is my problem.-2(5n+5)+6(n-8). I don't understand the order of operations or how to solve.1 solutions Answer 232444 by rfer(12660)   on 2010-07-22 12:35:42 (Show Source): You can put this solution on YOUR website!remember please excuse my dear aunt sally () x^2 * / + - -2(5n+5)+6(n-8) -10n-10+6n-48 -4n-58
 Rectangles/324677: he perimeter of a rectangle is 66cm if the length is twice the width,what are the dimension of the rectangle?1 solutions Answer 232442 by rfer(12660)   on 2010-07-22 12:29:13 (Show Source): You can put this solution on YOUR website!2w+2(2w)=66 6w=66 w=11 cm 2w=22 cm
 percentage/324712: What is the value of the expression 2x2+3xy-when x=2 and y= -41 solutions Answer 232441 by rfer(12660)   on 2010-07-22 12:26:11 (Show Source): You can put this solution on YOUR website!2*2^2+3*2*-4 8-24=-16
 Numeric_Fractions/324592: Simplify (1/4)(-2/7)(5/8)(7/6)1 solutions Answer 232346 by rfer(12660)   on 2010-07-22 01:19:50 (Show Source): You can put this solution on YOUR website!-2/28*5/8=-10/224 -10/224*7/6=-70/1344=-5/96
 Equations/324591: solve 1/3=n/ 4 1/71 solutions Answer 232345 by rfer(12660)   on 2010-07-22 01:17:29 (Show Source): You can put this solution on YOUR website!n=1/3*4 1/7 n=1/3*29/7 n=29/21 n=1 8/21
 Angles/324497: give the measure of the angle that is complementary to an angle the measures 71 degrees 1 solutions Answer 232256 by rfer(12660)   on 2010-07-21 20:17:03 (Show Source): You can put this solution on YOUR website!90-71=19 degrees
 Polynomials-and-rational-expressions/324467: is 6abcxyz a trinomial a binomial or a monomial?1 solutions Answer 232231 by rfer(12660)   on 2010-07-21 16:49:48 (Show Source): You can put this solution on YOUR website!monomial, it has just one term
 Volume/324457: could you please tell me how many litres would fill a container measuring 9ft x 8ft x 2.5ft1 solutions Answer 232230 by rfer(12660)   on 2010-07-21 16:47:27 (Show Source): You can put this solution on YOUR website!9*8*2.5=180 cu ft 180*28.32=5097.6 liters
 Linear-equations/324342: determine the present value you must invest to have a future value of \$8,500 when the simple interest rate is 7% for 3 years1 solutions Answer 232226 by rfer(12660)   on 2010-07-21 16:25:15 (Show Source): You can put this solution on YOUR website!A=P(1+r)^n P=A/((1+r)^n) P=8500/((1.07)^3) P=8500/1.225 P=6938.78