Tutor:

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

---

Recent problems solved by 'rfer'

rfer answered: 12653 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

Probability-and-statistics/452552: If a coin is flipped four times, what is the probabilty of flipping tails all four times? Please show work 1 solutions Answer 311093 by rfer(12657)   on 2011-05-22 12:57:00 (Show Source): You can put this solution on YOUR website! 1/2*1/2*1/2*1/2=1/16

Linear-equations/450917: Write the slope-intercept equation for the line that passes through (6, -9) and has slope -7/6. Please show all of your work 1 solutions Answer 310133 by rfer(12657)   on 2011-05-17 22:07:48 (Show Source): You can put this solution on YOUR website! -9=-7/6*6+b -9=-7+b b=-9+7 b=-2 ------------- y=-7/6x-2

Numeric_Fractions/450909: Solve. Please show all of your work. During one year, the Wagners' real estate bill included $600 for local schools. Of this amount, $150 went to the high school district. What percent did the Wagner family pay to the high school district? 1 solutions Answer 310131 by rfer(12657)   on 2011-05-17 22:03:36 (Show Source): You can put this solution on YOUR website! 150/600=0.25=25%

test/450943: 9x-22=23+4x 1 solutions Answer 310130 by rfer(12657)   on 2011-05-17 22:01:51 (Show Source): You can put this solution on YOUR website! 5x=45 x=9

Linear-equations/450916: Write the slope-intercept equation for the line with slope 1/2 and y-intercept (0, -5) and graph the line. 1 solutions Answer 310129 by rfer(12657)   on 2011-05-17 22:00:13 (Show Source): You can put this solution on YOUR website! y=1/2x-5

logarithm/450990: what is x+1/3 = x+5/x? 1 solutions Answer 310128 by rfer(12657)   on 2011-05-17 21:58:18 (Show Source): You can put this solution on YOUR website! 1/3=5/x x=15

Quadratic_Equations/450968: Solve: 9-3(2x-5)=4x-6 Please show me the steps to get the answer. Thanks 1 solutions Answer 310126 by rfer(12657)   on 2011-05-17 21:57:07 (Show Source): You can put this solution on YOUR website! 9-6x+15=4x-6 -10x=-30 x=3

Quadratic_Equations/450973: Find equation of line passing through the point: (5,-2) and (-3,4) Please show me the steps to get the answer. Thanks 1 solutions Answer 310125 by rfer(12657)   on 2011-05-17 21:55:13 (Show Source): You can put this solution on YOUR website! slope m=(4--2)/(-3-5) m=6/-8 m=-3/4 ------------ y=mx+b -2=-3/4*5+b -2=-15/4+b -8/4+15/4=b 7/4=b b=1 3/4 ------------- y=-3/4x+1 3/4

Proportions/450980: -6/x=3/ 11/30 solve the proportion 1 solutions Answer 310122 by rfer(12657)   on 2011-05-17 21:50:13 (Show Source): You can put this solution on YOUR website! 3x=-66/30 x=-66/30*1/3 x=-66/90 x=-11/15

Inequalities/450983: 2b + 5 < -1 or b - 4 > -4 1 solutions Answer 310120 by rfer(12657)   on 2011-05-17 21:48:12 (Show Source): You can put this solution on YOUR website! 2b < -6 b < -3 ----------- b > 0

test/450532: 8(10-4a)+15=-3(a+7) 1 solutions Answer 309893 by rfer(12657)   on 2011-05-17 10:04:48 (Show Source): You can put this solution on YOUR website! 80-32a+15=-3a-21 -29a=-116 a=4

decimal-numbers/450391: If you have a problem in rounding like this- 12.37 and it says to round it to the 3 would the answer be like this? 12.40? 1 solutions Answer 309802 by rfer(12657)   on 2011-05-16 21:00:14 (Show Source): You can put this solution on YOUR website! your correct, except you don't need the zero. 12.4

percentage/450309: A suit is made of 60% wool and 40% polyester. a) What fractional part of the suit is wool? b) What fractional part of the suit is polyester? 1 solutions Answer 309799 by rfer(12657)   on 2011-05-16 20:54:20 (Show Source): You can put this solution on YOUR website! A) W=3/5 B) P=2/5

Polynomials-and-rational-expressions/450379: which expression or value is a term in 12w to the 3rd power plus 8 1 solutions Answer 309797 by rfer(12657)   on 2011-05-16 20:50:54 (Show Source): You can put this solution on YOUR website! 12w^3+8

expressions/450327: #1. Do you know how to solve 4r + 5r = 45 #2. Do you know how to solve 2a + 9a =88 #3. Do you know how to solve r dicided by 3 - r divided by 5 = 4 divided by 15 #4. Do you know how to solve 7c divied by 10 - c divided by 5 = 9 divied by 2 1 solutions Answer 309795 by rfer(12657)   on 2011-05-16 20:48:40 (Show Source): You can put this solution on YOUR website! 1) 9r=45 r=45/9 r=5 3) r/3-r/5=4/15 5r/15-3r/15=4/15 2r/15=4/15 2r=4/15*15/1 2r=4 r=4/2 r=2

Linear-equations/450374: graph the equation using the slope and the y-intercept. y= -8/3x - 6. I need help graphing it. what are the points? there should be three correct? 1 solutions Answer 309788 by rfer(12657)   on 2011-05-16 20:43:09 (Show Source): You can put this solution on YOUR website! y=mx+b m=slope b=y int slope=-8/3 y int=-6 (0,-6) ---------------- y int is first point. 2nd point 3 right, 8 down from y int. 3rd point 3 right, 8 down from (3,-14) no math necessary.

Linear-equations/450337: I cant determine if this equation is a linear equation. xy = 6 1 solutions Answer 309785 by rfer(12657)   on 2011-05-16 20:39:01 (Show Source): You can put this solution on YOUR website! It is linear because no exponents are used.

Pythagorean-theorem/450352: How do you do pythagorean triple? 1 solutions Answer 309783 by rfer(12657)   on 2011-05-16 20:36:48 (Show Source): You can put this solution on YOUR website! the triple needs no work 3, 4, 5, or 6, 8, 10 and so on. You will find most tests use the triples so just remember them.

Miscellaneous_Word_Problems/450358: in a survey 29% of respondents reported that they have returned rented videotapes to the store late. if 3200 people responded to the survey, how many returned a video tape late ? 1 solutions Answer 309781 by rfer(12657)   on 2011-05-16 20:34:10 (Show Source): You can put this solution on YOUR website! 3200*0.29=928

Miscellaneous_Word_Problems/450363: the price of an oil change increased from $19.95 to $22.95. what was the percent of increase? 1 solutions Answer 309779 by rfer(12657)   on 2011-05-16 20:31:25 (Show Source): You can put this solution on YOUR website! 3/19.95=0.15=15%

Miscellaneous_Word_Problems/450362: the regular cost of a paperback book is $6.95. if all paperbacksare on sale at a 25% discount, what is the sale cost of a paperback book? 1 solutions Answer 309778 by rfer(12657)   on 2011-05-16 20:29:57 (Show Source): You can put this solution on YOUR website! 6.95*0.75=$4.88

Money_Word_Problems/450305: A surprise retirement party is being planned for Pratep Puri. A total of $860 has been collected for the event, which is to be held at a local reception hall. This reception hall charges a cleanup fee of $40 and $15 per person for drinks and light snacks. Find the greatest number of people that may be invited and still stay within $860. 1 solutions Answer 309747 by rfer(12657)   on 2011-05-16 19:00:56 (Show Source): You can put this solution on YOUR website! 860-40=820 820/15=54 people

Travel_Word_Problems/450302: Vacation trip from Washington, D.C.to San Francisco. 5 days travel time and 2800 miles. If I travel 100 miles per day less than the day before, how many miles do I travel each day? Thank you 1 solutions Answer 309746 by rfer(12657)   on 2011-05-16 18:59:24 (Show Source): You can put this solution on YOUR website! x+x-100+x-200+x-300+x-400=2800 5x-1000=2800 5x=2800+1000 5x=3800 x=760 day 1 x-100=660 day 2 x-200=560 day 3 x-300=460 day4 x-400=360 day5

Sequences-and-series/450297: #1. Do you know how to solve for 3m + 2m = 15 #2. Do you know how to solve for 4r + 5r +45 #3. Do you know how to solve for 10p - 7p = 18 #4. Do you know how to solve for 2a + 9a = 88 #5. Do you know how to solve for 5y + 4y - 11 = 16 1 solutions Answer 309744 by rfer(12657)   on 2011-05-16 18:54:59 (Show Source): You can put this solution on YOUR website! 1) 3m+2m=15 5m=15 m=15/5 m=3 3) 10p-7p=18 3p=18 p=18/3 p=6 5) 5y+4y-11=16 9y=16+11 9y=27 y=27/9 y=3 You try the others

logarithm/450292: 3 In 5 1 solutions Answer 309738 by rfer(12657)   on 2011-05-16 18:43:15 (Show Source): You can put this solution on YOUR website! 3/5=0.60=60%

expressions/450269: Volume of cone: Base is 20ft H is 10ft 1 solutions Answer 309737 by rfer(12657)   on 2011-05-16 18:42:29 (Show Source): You can put this solution on YOUR website! V=(3.14*r^2*h)/3 V=(3.14*10^2*10)/3 V=3140/3 V=1047 cuft

Exponents-negative-and-fractional/450284: -1(-4) 1 solutions Answer 309736 by rfer(12657)   on 2011-05-16 18:38:00 (Show Source): You can put this solution on YOUR website! -1(-4)=+4

Evaluation_Word_Problems/450289: Independent and Dependent events: Probability Steven rolled a 1-6 number cube four times. The result was 4 odd numbers. 1 solutions Answer 309735 by rfer(12657)   on 2011-05-16 18:36:34 (Show Source): You can put this solution on YOUR website! .5*.5*.5*.5=0.062=6.26%

Graphs/449930: solve by substition method. 2m+n=1 m-7n=38 1 solutions Answer 309637 by rfer(12657)   on 2011-05-16 12:17:58 (Show Source): You can put this solution on YOUR website! 2m+n=1 n=1-2m m-7n=38 m-7(1-2m)=38 m-7+14m=38 15m=45 m=3 ------------- 3-7n=38 -7n=35 n=-5 ------------ 2*3+-5=1

Exponents/449942: write the following numbers in a short form using indices/powers (a)5*5*5*5*5*5*5*5 (b)3*7*3*7*7*7*3*7 1 solutions Answer 309635 by rfer(12657)   on 2011-05-16 12:13:56 (Show Source): You can put this solution on YOUR website! A) 5^8 B) 3^3*7^5

Points-lines-and-rays/449980: What is the y axis of (2,4), (3,10), and (4,8)? 1 solutions Answer 309634 by rfer(12657)   on 2011-05-16 12:09:43 (Show Source): You can put this solution on YOUR website! (x,y)