Tutor:

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

---

Recent problems solved by 'rfer'

rfer answered: 12674 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

Money_Word_Problems/261062: I need help setting up this problem please. Tickets to a recital cost $2.00 for children, $5.00 for adults and $3.00 for seniors citizens. After the recital, the organizers find that 570 people attended, and $1,950 was earned from ticket sales.However,they are unable to find a record of exactly how many children,adults,and senior citizens attended. All they can find is a cryptic note from the theater manager stating that three-fourths as many senior citizens as children attended 1 solutions Answer 192326 by rfer(12678)   on 2010-01-25 21:14:14 (Show Source): You can put this solution on YOUR website! C+.75C+A=570 1.75C+A=570 A=570-1.75C ----------------- 2C+3(.75C)+5A=1950 -------------------- 2C+2.25C+5(570-1.75C) 2C+2.25C+2850-8.75C=1950 -4.5C=-900 C=225 Children .75C=169 Seniors A=176 Adults

Linear-equations/261057: How do you change y+4=-3/4(x-1) to standard form? 1 solutions Answer 192317 by rfer(12678)   on 2010-01-25 20:53:13 (Show Source): You can put this solution on YOUR website! y+4=-3/4(x-1) y+4=-3/4x+3/4 3/4x+y=3 1/4

Evaluation_Word_Problems/261060: Find sqrt( 1-a^2)x b when a = 0.28 and b = 10 I tried sqrt( 1 - (0.28)^2) x 10 = 9.6 is that right? 1 solutions Answer 192315 by rfer(12678)   on 2010-01-25 20:49:37 (Show Source): You can put this solution on YOUR website! That is what I get also. Bob

Polynomials-and-rational-expressions/260971: 2x-3(x+5)= -3x+7 1 solutions Answer 192276 by rfer(12678)   on 2010-01-25 19:38:28 (Show Source): You can put this solution on YOUR website! 2x-3(x+5)=-3x+7 2x-3x-15=-3x+7 2x=22 x=11

Miscellaneous_Word_Problems/261000: A dealer bought some bikes for $2,000. She sold them for $2,400, making 50 dollars on each bike. How many bikes were involved? 1 solutions Answer 192273 by rfer(12678)   on 2010-01-25 19:32:02 (Show Source): You can put this solution on YOUR website! 2400-2000/50=8 bikes

Linear-equations/260975: What is the slope of a line with the equation 4x + 12y = 6? 1 solutions Answer 192265 by rfer(12678)   on 2010-01-25 19:21:48 (Show Source): You can put this solution on YOUR website! 4x+12y=6 12y=-4x+6 y=-4/12x+6/12 y=-1/3x+1/2 slope=m=-1/3

Linear-systems/260987: Help !! "solve each of the equations" -2x+3y =-9 y= ????? 1 solutions Answer 192264 by rfer(12678)   on 2010-01-25 19:18:47 (Show Source): You can put this solution on YOUR website! -2x+3y=-9 3y=2x-9 y=2/3x-3

Circles/260986: What is the approximate area of a fourth of a circle with a radius of six inches? 1 solutions Answer 192260 by rfer(12678)   on 2010-01-25 19:15:41 (Show Source): You can put this solution on YOUR website! A=3.14*6^2*.25 A=28.26 sq in

Rectangles/260985: The length of a rectangle is four times the width. the perimeter is ninety cm. what is the width and length. 1 solutions Answer 192257 by rfer(12678)   on 2010-01-25 19:13:32 (Show Source): You can put this solution on YOUR website! 90=2x+2(4x) 90=2x+8x 90=10x x=9 cm 4x=36 cm

Inequalities/260984: my cousin is in 7th grade and i understand how to work a inequalitie such as x+5<20 . i just do not understand how to work one with a fraction and negitive sign in it such as (-1/3)x>30 . please help ! 1 solutions Answer 192254 by rfer(12678)   on 2010-01-25 19:11:47 (Show Source): You can put this solution on YOUR website! (-1/3)x >30 x > 30/(-1/3) x > 30*-3/1 x > -90

Mixture_Word_Problems/260337: There are four times as many trumpets as flute players in the orchestra. If there are 70 trumpet and flute players, how many flutes players are there 1 solutions Answer 191773 by rfer(12678)   on 2010-01-24 14:30:00 (Show Source): You can put this solution on YOUR website! x+4x=70 5x=70 x=14 flutes

Numbers_Word_Problems/260346: the second of two numbrs is 8 more than the first. their sum is 20. find the two numbers 1 solutions Answer 191771 by rfer(12678)   on 2010-01-24 14:27:24 (Show Source): You can put this solution on YOUR website! x+x+8=20 2x+8=20 2x=12 x=6 x+8=14

Graphs/260131: Write the equation of the line with slope -9 and y intercept (0,4) 1 solutions Answer 191582 by rfer(12678)   on 2010-01-23 20:42:33 (Show Source): You can put this solution on YOUR website! y=-9x+4

Money_Word_Problems/260140: the suggested list price of a new car is $34000. the dealer's cost is 85% of list. How much will you pay if the dealer is willing to accept $100 over cost for the car? 1 solutions Answer 191581 by rfer(12678)   on 2010-01-23 20:41:29 (Show Source): You can put this solution on YOUR website! 34000*.85+100=$29,000

Linear_Algebra/259883: solve each linear equation using any technique name the technique 3x/4 + 6 = -12 1 solutions Answer 191376 by rfer(12678)   on 2010-01-22 21:29:11 (Show Source): You can put this solution on YOUR website! 3x/4+6=-12 3x/4=-18 3x=-18*4 3x=-72 x=-24

test/259917: 1/4 + 5/6 1 solutions Answer 191373 by rfer(12678)   on 2010-01-22 21:25:26 (Show Source): You can put this solution on YOUR website! 1/4+5/6 3/12+10/12=13/12= 1 1/12

Equations/259889: I am a parent that didn't get to finish in high school and my son has this problem and i don't know to write the equation out. thank you for your time. Here is the problem. Air Travel: A jet leaves the Chalotte, Noth Carolina, airport traveling at an aveage rate of 564 km/h. Another plane leaves the airport one half hour later traveling at 744 km/h in the same direction. Use an equation to find how long the second jet will take to overtake the first. 1 solutions Answer 191348 by rfer(12678)   on 2010-01-22 20:06:43 (Show Source): You can put this solution on YOUR website! overtake speed is 744-564=180 km/h A is 564/2=282km ahead 282/180=1.57 hrs or 1hr 34 min for B to overtake A

Permutations/259811: A $152,400 loan is taken out, at 11.5% for 25 years, for the purchase of a house. The loan requires monthly payments. Find the amount of each payment. 1 solutions Answer 191347 by rfer(12678)   on 2010-01-22 20:02:25 (Show Source): You can put this solution on YOUR website! PMT=(L*i*(1+i)^300)/((1+i)^300-1) PMT=(152400*.115*(1.115)^300)/(1.115)^300-1

Equations/259281: 4x+15 = 7x-6 1 solutions Answer 190896 by rfer(12678)   on 2010-01-21 12:48:18 (Show Source): You can put this solution on YOUR website! 4x+15=7x-6 21=3x x=7

Geometry_Word_Problems/259108: A tree cast a shadow 60 Feet long. At the same time, an 8-foot post casts a 12-foot shadow. How tall is the tree 1 solutions Answer 190812 by rfer(12678)   on 2010-01-21 01:16:41 (Show Source): You can put this solution on YOUR website! 60/x=12/8 12x=480 x= 40 ft tall

Geometry_Word_Problems/259112: A Flagpole casts a 75-foot shadow at the same time a tree 20 feet tall casts a shadow of 30 feet. How tall is the flagpole 1 solutions Answer 190811 by rfer(12678)   on 2010-01-21 01:14:14 (Show Source): You can put this solution on YOUR website! 20/30=x/75 30x=1500 x=50 ft tall

Geometry_Word_Problems/259113: A local monument casts a shadow 111 feet long at the same time a 50-foot telephone pole casts a shadow 10 feet long. How high is the monument? 1 solutions Answer 190810 by rfer(12678)   on 2010-01-21 01:12:17 (Show Source): You can put this solution on YOUR website! 50/10=x/111 10x=5550 x=555 ft high

Finance/259135: Ben is making wooden toys for the next arts and crafts sale. Each toy costs Ben $1.80 to make. If he sells the toys for $3.00 each, how many will he have to sell to make a profit of exactly $36.00 ? A. 12 B. 20 C. 30 D. 60 E. 108 1 solutions Answer 190809 by rfer(12678)   on 2010-01-21 01:08:27 (Show Source): You can put this solution on YOUR website! 3-1.8=1.2 36/1.2=30 Answer C

expressions/259137: -3/4 x -1/3 + 7/8 x -1/2 1 solutions Answer 190808 by rfer(12678)   on 2010-01-21 01:05:17 (Show Source): You can put this solution on YOUR website! -3/4x-1/3+7/8x-1/2 -6/8x-2/6+7/8x-3/6 1/8x-5/6 find common denominators then combine like terms

Functions/259163: My question is in regards to graphing linear functions. I need to graph y=2/3x-4 I am unsure how to graph it. Could you also explain why I graph it the way I do based on that formula. Thanks a lot. ANy help is appreciated. 1 solutions Answer 190807 by rfer(12678)   on 2010-01-21 01:01:53 (Show Source): You can put this solution on YOUR website! you have a slope intercept equation y=mx+b y=2/3x-4 y int= -4 (0,-4) m=slope=2/3 the rise over the run so next point is (3,-2)

Numeric_Fractions/259144: First Question: 7/14 + 3/14 + 8/14= Second Question: 4 1/2 - 8 1/5= 1 solutions Answer 190806 by rfer(12678)   on 2010-01-21 00:58:27 (Show Source): You can put this solution on YOUR website! 1) 7/14+3/14+8/14=18/14=1 2/7 2) 4 1/2-8 1/5 45/10-82/10= -37/10= -3 7/10

absolute-value/259146: nate runs 8miles each week. Write an expression for the number of miles he runs in n weeks. Find the number of miles nate runs in 5 weeks? 1 solutions Answer 190805 by rfer(12678)   on 2010-01-21 00:53:44 (Show Source): You can put this solution on YOUR website! D=r*n D=8*5 D=40 miles

Travel_Word_Problems/259150: it is a 42 km drive go oakdale to ridgemont and takes 28 min. Because of traffic and construction working the trip is now 14 minutes longer. find the reduced speed limit in km/h 1 solutions Answer 190804 by rfer(12678)   on 2010-01-21 00:51:45 (Show Source): You can put this solution on YOUR website! r=D/t r=42/.07 hrs r=60 km/h

Travel_Word_Problems/259156: Jim drives to Hermiston at 80mph. If Hermiston is 30 miles away how long does it take to get there (in hours)? 1 solutions Answer 190803 by rfer(12678)   on 2010-01-21 00:46:24 (Show Source): You can put this solution on YOUR website! t=D/r t=30/80 t=0.375 hrs or 22.5 min

Travel_Word_Problems/259159: If you drive 315 miles in 6 hours, how long will it take you to drive an additional 85 miles at the same rate of speed? 1 solutions Answer 190801 by rfer(12678)   on 2010-01-21 00:42:29 (Show Source): You can put this solution on YOUR website! 315/6=85/x 315x=510 x=510/315 x=1.6 hrs or 1 hr 36 min

Equations/259160: solve the equation 7x+2=23? and 12-5x=16 1 solutions Answer 190800 by rfer(12678)   on 2010-01-21 00:39:56 (Show Source): You can put this solution on YOUR website! 7x+2=23 7x=21 x=3 ------------- 12-5x=16 -5x=4 x=-4/5