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

Trigonometry-basics/305133: 4(b-3)=7 1 solutions Answer 218496 by rfer(12670)   on 2010-05-16 19:30:15 (Show Source): You can put this solution on YOUR website! 4(b-3)=7 4b-12=7 4b=19 b=4.75

Finance/305177: the sum of two numbers is 24. the first number is 4 more than the second. what are the numbers? 1 solutions Answer 218494 by rfer(12670)   on 2010-05-16 19:24:57 (Show Source): You can put this solution on YOUR website! x+x+4=24 2x+4=24 2x=20 x=10 x+4=14

Linear-equations/303426: 5x-2y+10 graph by using the slope and y intercept 1 solutions Answer 217506 by rfer(12670)   on 2010-05-11 21:01:35 (Show Source): You can put this solution on YOUR website! 2y=5x-10 y=2.5x-5 y int (0,-5) slope m =2.5

Volume/303350: Reina is constructing a cylinder that can hold 90.8 cubic centimeters. If the diameter of the cylinder is 3.4 centimeters, what should the height measure? (Round to the nearest tenth.) 1 solutions Answer 217447 by rfer(12670)   on 2010-05-11 17:57:54 (Show Source): You can put this solution on YOUR website! 3.14*1.7^2=9.0746 90.8/9.0746=10.0 cm

Linear-equations/303245: Find the slope of the line passing through the points A(-2,-5)and B(-1,-3). 1 solutions Answer 217373 by rfer(12670)   on 2010-05-11 15:57:02 (Show Source): You can put this solution on YOUR website! slope of 2

Quadratic_Equations/303287: To get the maximum space for 10 ft of fence, what dimensions should be used- How would this be identified using a quadratic equation? 1 solutions Answer 217368 by rfer(12670)   on 2010-05-11 15:53:20 (Show Source): You can put this solution on YOUR website! A square is the max area. 2.5 ft by 2.5 ft area

Angles/303288: a complementary angle to a 31 degree angle has a measure of________? 1 solutions Answer 217367 by rfer(12670)   on 2010-05-11 15:51:52 (Show Source): You can put this solution on YOUR website! 90-31=59 degrees

Miscellaneous_Word_Problems/303055: If glen owns 12 trees more than twice what mary does, and together they own 72 trees, hown many does each one own? 1 solutions Answer 217221 by rfer(12670)   on 2010-05-10 23:06:36 (Show Source): You can put this solution on YOUR website! x+x+12=72 2x=60 x=30 x+12=42

Distributive-associative-commutative-properties/302099: 15x-10x its using distributive property and simplify if possible not sure how to do it 1 solutions Answer 216652 by rfer(12670)   on 2010-05-08 22:12:35 (Show Source): You can put this solution on YOUR website! 15x-10x=5x

Linear-systems/301755: solve each system using the subsitution method. y=5x-1 y-3x=1 1 solutions Answer 216412 by rfer(12670)   on 2010-05-07 19:58:02 (Show Source): You can put this solution on YOUR website! 5x-1-3x=1 2x=2 x=1 ----------- y=5*1-1 y=4 ------------- 4-3*1=1

Money_Word_Problems/301824: Jon and Lauren have a combined income of $48,000. Lauren earns $3000 more than half of what Jon earns. Find the individual income of each. 1 solutions Answer 216411 by rfer(12670)   on 2010-05-07 19:54:32 (Show Source): You can put this solution on YOUR website! x+(.5x+3000)=48000 1.5x=45000 x=$30,000 .5x+3000=$18,000

Miscellaneous_Word_Problems/301767: Suppose you deposit $1000 earned from your summer job in a savings account, paying 4.8% compounded annually. How much will you have in your account after 3 years? Write an equation to model the problem and then solve your equation for the given value. 1 solutions Answer 216410 by rfer(12670)   on 2010-05-07 19:51:06 (Show Source): You can put this solution on YOUR website! A=P(1+r)^t A=1000(1+.048)^3 A=1000(1.151) A=$1151

Equations/301801: If the sales tax rate 7.5% and the tax 0n a purchase is $45 what was the amount of purchase? 1 solutions Answer 216407 by rfer(12670)   on 2010-05-07 19:45:10 (Show Source): You can put this solution on YOUR website! 45/.075=$600

Travel_Word_Problems/301809: Two cars are traveling toward each other, starting at the same time 480km apart. If they meed after four hours, and one care is traveling 40kph faster than the other, how fast is each car moving? Thanks for your help. 1 solutions Answer 216406 by rfer(12670)   on 2010-05-07 19:43:00 (Show Source): You can put this solution on YOUR website! (x+x+40)(4)=480 (2x+40)(4)=480 8x+160=480 8x=320 x=40 kph x+40=80 kph

Percentage-and-ratio-word-problems/301817: Last summer, a surfboard was selling for $325. This summer, last year's model of that same board is being sold for $275. What is the percent of decrease, rounded to the nearest whole percentage? 1 solutions Answer 216404 by rfer(12670)   on 2010-05-07 19:37:49 (Show Source): You can put this solution on YOUR website! 50/325=.15=15%

Radicals/301501: the square root of 8 over the square root of 5 1 solutions Answer 216214 by rfer(12670)   on 2010-05-06 21:41:24 (Show Source): You can put this solution on YOUR website! sq rt 8/sq rt 5 8/5=1.6 sq rt 1.6=1.2649

Graphs/301505: what is the x and y intercept of 3x+6y=18 1 solutions Answer 216213 by rfer(12670)   on 2010-05-06 21:36:13 (Show Source): You can put this solution on YOUR website! 3x+6y=18 3x+6*0=18 x=6 ---------- x int (6,0) ------------ 6y=-3x+18 y=-1/2x+3 --------------- y int (0,3)

Equations/301548: can you please help me solve the equation 5-x-x=-1 1 solutions Answer 216212 by rfer(12670)   on 2010-05-06 21:26:42 (Show Source): You can put this solution on YOUR website! 5-x-x=-1 -2x=-6 x=3

Probability-and-statistics/301549: You work at a T-shirt printing business. 564 of 4,700 T-shirts shipped are printed improperly. Predict the number of improperly printed T-shirts in a batch of 2,000. 1 solutions Answer 216211 by rfer(12670)   on 2010-05-06 21:25:44 (Show Source): You can put this solution on YOUR website! 564/4700=x/2000 4700x=1128000 x=240

Percentage-and-ratio-word-problems/301276: a car dealer valued a car used as a trade-in at $3,816. he offered it for sale for $8,586. what percent of the frade-in value is the selling price? 1 solutions Answer 216041 by rfer(12670)   on 2010-05-06 10:55:06 (Show Source): You can put this solution on YOUR website! 8586/3816=2.25=225%

Linear-equations/297479: How do I solve this equation?-- 1/4(x-8)=7 1 solutions Answer 214213 by rfer(12670)   on 2010-04-27 20:12:05 (Show Source): You can put this solution on YOUR website! .25(x-8)=7 .25x-2=7 .25x=9 x=36 or 1/4(x-8)=7 x-8=7*4 x-8=28 x=36

Sequences-and-series/297472: The lengths of the sides of a triangle are three consecutive whole numbers. The perimieter is 153cm. Determine the length of the three sides and give a complete algebraic solution? Thanks everyone!! 1 solutions Answer 214212 by rfer(12670)   on 2010-04-27 20:09:32 (Show Source): You can put this solution on YOUR website! x+x+1+x+2=153 3x+3=153 3x=150 x=50 x+1=51 x+2=52

Square-cubic-other-roots/297471: what is i to the 50th power? 1 solutions Answer 214211 by rfer(12670)   on 2010-04-27 20:07:02 (Show Source): You can put this solution on YOUR website! answer = 1

Distributive-associative-commutative-properties/297416: -6-3+8 1 solutions Answer 214179 by rfer(12670)   on 2010-04-27 18:22:30 (Show Source): You can put this solution on YOUR website! =-1

Travel_Word_Problems/297352: two trains travel in the same direction on parallel track train a goes 50 kilometers ahead of train b train a goes 90 kilometers train b goes 100 kilometers in how many hours will the train meet 1 solutions Answer 214177 by rfer(12670)   on 2010-04-27 18:21:52 (Show Source): You can put this solution on YOUR website! 50 k lead 10 k overtake speed 50/10=5 hrs

Volume/297411: the bottom of the box is 10 1/2 inches long and 5 inches wide. The box is 3 inches high. what is the volume of the box? 1 solutions Answer 214176 by rfer(12670)   on 2010-04-27 18:19:15 (Show Source): You can put this solution on YOUR website! 10.5*5*3=157.5 sq in

Travel_Word_Problems/297387: The distance, d, an automobile travels after the brakes have been applied varies directly as the square of the speed, s. If the stopping distance for a car going 30 mph is 54 feet, what is the stopping distance for a car going 70 mph? 1 solutions Answer 214175 by rfer(12670)   on 2010-04-27 18:17:58 (Show Source): You can put this solution on YOUR website! 30^2/54=70^2/x 900/54=4900/x 900x=264600 x=294 ft

Linear-equations/297390: Find the slope that each line passes through 1:)A(-10, 6), B(-5,8) 1 solutions Answer 214174 by rfer(12670)   on 2010-04-27 18:14:37 (Show Source): You can put this solution on YOUR website! m=5/2

Rectangles/297397: How to find the length and width of the rectangle if the perimeter is 48 and the length is 4 in greater than the width? 1 solutions Answer 214172 by rfer(12670)   on 2010-04-27 18:11:03 (Show Source): You can put this solution on YOUR website! 2x+2(x+4)=8 4x+8=48 4x=40 x=10 x+4=14

Rectangles/296987: a company is designing a rectangular stage to have an area of 900 ft sq2. The length must be 36ft. what would be the width? 1 solutions Answer 213913 by rfer(12670)   on 2010-04-26 20:06:37 (Show Source): You can put this solution on YOUR website! 900/36=25 ft

Numeric_Fractions/296914: y = -2/3(-6) + 1 1 solutions Answer 213911 by rfer(12670)   on 2010-04-26 20:04:44 (Show Source): You can put this solution on YOUR website! y=-2/3(-6)+1 y=(-2/3)(-6/1)+1 y=12/3+1 y=4+1 y=5