Tutor:

New! Get regular updates about newly solved problems via algebra.com's RSS system.

---

Recent problems solved by 'rfer'

rfer answered: 12666 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 , 12660..12689, >>Next

percentage/679770: robert and elena usually order a medium pizza for 15.00. the large pizza cost 40% more 1 solutions Answer 422050 by rfer(12670)   on 2012-11-13 12:28:53 (Show Source): You can put this solution on YOUR website! 15*1.40=21

Percentage-and-ratio-word-problems/679730: $1,200 TV; 10% discount sales price 1 solutions Answer 422049 by rfer(12670)   on 2012-11-13 12:28:01 (Show Source): You can put this solution on YOUR website! 1200*0.90=$1080

Linear-equations/679747: Write the equation in standard form : Y=(-2/3) x + 1/8 1 solutions Answer 422047 by rfer(12670)   on 2012-11-13 12:24:45 (Show Source): You can put this solution on YOUR website! 2/3x+y=1/8

Equations/679764: you've just got a job selling electronics at a commission. In your first week you got paid 33.75 for sales of 450 of goods. what is your commission rate (as a percentage) 1 solutions Answer 422046 by rfer(12670)   on 2012-11-13 12:23:39 (Show Source): You can put this solution on YOUR website! 33.75/450=0.075=7.5%

Systems-of-equations/679768: A rectangular picture has a height that is 5/7 of its width. Its area is 140 square inches. What are the dimensions of the picture? 1 solutions Answer 422045 by rfer(12670)   on 2012-11-13 12:21:29 (Show Source): You can put this solution on YOUR website! 5x*7x=140 35x^2=140 x^2=140/35 x^2=4 x=2 5x=10 7x=14

Equations/679570: The temperature fell 16 degrees between noon and 3 p.m. At 3p.m., the temperature was -3 degrees. Write an equation to determine the temperature at noon. 1 solutions Answer 421976 by rfer(12670)   on 2012-11-12 21:53:49 (Show Source): You can put this solution on YOUR website! t=-3+16 t=13 at noon

Age_Word_Problems/679314: Twice the number increased by 33 is 93.Three times a number decreased by 26 is 49.Twenty-five less than 5 times a number is 225.Five times a number is 6 less than 481.Two less than 4 times a number is 86. 1 solutions Answer 421919 by rfer(12670)   on 2012-11-12 17:10:04 (Show Source): You can put this solution on YOUR website! 2x+33=93 2x=93-33 2x=60 x=60/2 x=30

Numeric_Fractions/679299: X-7/7 = 2x/4 1 solutions Answer 421917 by rfer(12670)   on 2012-11-12 17:04:32 (Show Source): You can put this solution on YOUR website! 4(x-7/7)=2x 4x-4=2x 4x-2x=4 2x=4 x=4/2 x=2

Money_Word_Problems/678919: If a business borrows $20,000 and repays $33,800 in 6 years, what is the simple interest rate? 1 solutions Answer 421677 by rfer(12670)   on 2012-11-11 21:09:00 (Show Source): You can put this solution on YOUR website! 13800/6=2300 2300/20000=0.115=11.5%

test/678951: How can I simplify the following expression? 6/3x-15 Thank you!!! =D 1 solutions Answer 421676 by rfer(12670)   on 2012-11-11 21:06:51 (Show Source): You can put this solution on YOUR website! 2x-15

Numeric_Fractions/678894: What Is 2/6 divided by 3/7 1 solutions Answer 421650 by rfer(12670)   on 2012-11-11 19:19:41 (Show Source): You can put this solution on YOUR website! 2/6*7/3=14/18=7/9

Linear-equations/678687: How can I find an equation of the line whose graph includes the following two points. (-1,4), (-3,-3). I think I have an idea on how to approach it, but I am uncertain. 1 solutions Answer 421580 by rfer(12670)   on 2012-11-11 10:41:59 (Show Source): You can put this solution on YOUR website! slope m=(-3-4)/(-3--1) m=-7/-2 m=3.5 ------------- y=mx+b -3=3.5*-3+b -3=-10.5 7.5=b ---------------- y=3.5x+7.5

Linear-systems/678535: 4x - y=9 is this ordered pair a solution of the given system of equations. 1 solutions Answer 421473 by rfer(12670)   on 2012-11-10 18:40:56 (Show Source): You can put this solution on YOUR website! What ordered pair?

Equations/678533: What is the error in this equation? m/3 - 9 = -21 m/3 - 9 + 9 = -21 + 9 m/3 = -12 m = -4 1 solutions Answer 421472 by rfer(12670)   on 2012-11-10 18:40:06 (Show Source): You can put this solution on YOUR website! The error is the last operation, it should be m=-12*3 m=-36

Equations/678418: What is the equation of 4-5c=-11 1 solutions Answer 421396 by rfer(12670)   on 2012-11-10 12:34:33 (Show Source): You can put this solution on YOUR website! -5c=-11-4 -5c=-15 c=-15/-5 c=3

test/678420: Measure of three angles using the ratio 1:2:3 if it is supplementary triangle 1 solutions Answer 421395 by rfer(12670)   on 2012-11-10 12:33:16 (Show Source): You can put this solution on YOUR website! x+2x+3x=180 6x=180 x=180/6 x=30 2x=60 3x=90

Percentage-and-ratio-word-problems/678448: a retailer bought a shirt for £300 andsold it for £225. what is the percentage decrease? 1 solutions Answer 421394 by rfer(12670)   on 2012-11-10 12:30:24 (Show Source): You can put this solution on YOUR website! 75/300=0.25=25%

Numeric_Fractions/678234: whats 6-3w=-27 1 solutions Answer 421218 by rfer(12670)   on 2012-11-09 11:49:21 (Show Source): You can put this solution on YOUR website! -3w=-27-6 -3w=-33 w=-33/-3 w=11

Numbers_Word_Problems/677690: The sum of two numbers is 68. One number is 4 more than the other. Find the two numbers. 1 solutions Answer 421009 by rfer(12670)   on 2012-11-08 11:43:53 (Show Source): You can put this solution on YOUR website! x+x+4=68 2x=68-4 2x=64 x=64/2 x=32 x+4=36

Systems-of-equations/677407: the sum of two numbers is 116. the largest number is 11 more than twice the smallest number. what are the two numbers 1 solutions Answer 420882 by rfer(12670)   on 2012-11-07 20:35:54 (Show Source): You can put this solution on YOUR website! x+2x+11=116 3x=116-11 3x=105 x=105/3 x=35 2x+11=81

test/677408: The sum of two numbers is 500. The difference between thesea two numbers is 220 . The smaller number is less than 200. The greater mumber is more than 300 1 solutions Answer 420881 by rfer(12670)   on 2012-11-07 20:32:24 (Show Source): You can put this solution on YOUR website! x+x-220=500 2x=500+220 x=720/2 x=360 x-220=140

percentage/677394: If 16 is increased to 23, the increase is what percent of the original number? 1 solutions Answer 420856 by rfer(12670)   on 2012-11-07 18:49:32 (Show Source): You can put this solution on YOUR website! 7/16=0.4375=43.75%

Proportions/677392: How do you set up the proportion for, what percent of 52 is 13 1 solutions Answer 420855 by rfer(12670)   on 2012-11-07 18:48:21 (Show Source): You can put this solution on YOUR website! 13/54=0.24=24%

Money_Word_Problems/677337: (future value) $5,100 invested for 10 years at $11 compounded annually will accumulate to ? ( round to the nearest cent) 1 solutions Answer 420854 by rfer(12670)   on 2012-11-07 18:47:09 (Show Source): You can put this solution on YOUR website! FV=5100(1.11)^10 FV=5100*2.83942 FV=$14,481.05

Money_Word_Problems/677350: If a game cost 45.00 and the controller 35.00, tax is 9.5% how much will you pay total 1 solutions Answer 420852 by rfer(12670)   on 2012-11-07 18:42:30 (Show Source): You can put this solution on YOUR website! 80*1.095=$87.60

test/677367: What is 60% out of 300 1 solutions Answer 420850 by rfer(12670)   on 2012-11-07 18:39:46 (Show Source): You can put this solution on YOUR website! 300*0.60=180

�t�e�s�t/677143: Write an equation of the line that is parallel to the given line y = 2x + 3 and the given point (-4,1). 1 solutions Answer 420709 by rfer(12670)   on 2012-11-07 12:16:46 (Show Source): You can put this solution on YOUR website! 1=2*-4+b 9=b y=2x+9

Money_Word_Problems/676980: The amount of an ordinary $7,500.00 annuity for 3 years at 12% compounded quarterly is: $23,182.50 $25,305.00 $180,997.50 $106,440.00 none of the above 1 solutions Answer 420649 by rfer(12670)   on 2012-11-07 01:02:13 (Show Source): You can put this solution on YOUR website! A=7500(1+0.12/4)^4*3 A=7500(1.03)^12 A=7500*1.42576 A=$10,693.20 None of the above

Money_Word_Problems/676722: Carlos invested $3,000 in a money market mutual fund that pays interest on a daily basis. The balance in his account at the end of 8 mo (245 days) was $3,183. Find the effective rate at which Carlos's account earned interest over this period (assume a 365-day year). A) 9.11%. B) 9.21%. C) 6.09%. D) 6.29%. 1 solutions Answer 420474 by rfer(12670)   on 2012-11-06 15:36:30 (Show Source): You can put this solution on YOUR website! A 9.11%

Money_Word_Problems/676721: Find the accumulated amount A if the principal P = $11,000 is invested at the interest rate of r = 5% per year for t = 5.5 years, compounded quarterly. 1 solutions Answer 420472 by rfer(12670)   on 2012-11-06 15:29:40 (Show Source): You can put this solution on YOUR website! A=11000(1+0.05/4)^4*5.5 A=11000(1.0125)^22 A=11000*1.31429=$14,457.00

Numeric_Fractions/676715: what is -1/7 minus 1 and 2/3 1 solutions Answer 420470 by rfer(12670)   on 2012-11-06 15:26:29 (Show Source): You can put this solution on YOUR website! -1/7-5/3= -3/21-35/21=-38/21=-1 17/21