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

Equations/463775: how can I solve this equation -2x + 5 = 13 1 solutions Answer 317712 by rfer(12657)   on 2011-06-23 11:13:20 (Show Source): You can put this solution on YOUR website! -2x=13-5 -2x=8 x=8/-2 x=-4

Equations/463784: what is the answer to 8x - 4 = 2x - 3 1 solutions Answer 317711 by rfer(12657)   on 2011-06-23 11:11:43 (Show Source): You can put this solution on YOUR website! 6x=1 x=1/6

Rectangles/463794: What is the maximum area that can be obtained from a rectangle if the perimeter is to be 45 inches? 1 solutions Answer 317710 by rfer(12657)   on 2011-06-23 11:09:34 (Show Source): You can put this solution on YOUR website! 45/4=11.25 A=11.25^2 A=126.56 sq in

Linear-equations/463796: How do solve this Linear equation problem -3u-19=2u+16 1 solutions Answer 317709 by rfer(12657)   on 2011-06-23 11:07:37 (Show Source): You can put this solution on YOUR website! -3u-2u=16+19 -5u=35 u=35/-5 u=-7

Complex_Numbers/463800: I don't understand how to do this question. I have to multiply (7t-8)(7t+8) 1 solutions Answer 317708 by rfer(12657)   on 2011-06-23 11:03:39 (Show Source): You can put this solution on YOUR website! (7t-8)(7t+8) 49t^2+56t-56t-64 answer 49^2-64

Number-Line/463806: Any point x lies between -7 to -1. What is the range of x ? 1 solutions Answer 317707 by rfer(12657)   on 2011-06-23 11:01:40 (Show Source): You can put this solution on YOUR website! range=6

Graphs/463807: Hi, I am having a little bit of difficuly and hoping one of you smart math tutors would be able to help me? :) Thank you so very much!!!!! Find the slope and the y-intercept of each line whose equation is given. y − 3 = 5 1 solutions Answer 317706 by rfer(12657)   on 2011-06-23 11:00:25 (Show Source): You can put this solution on YOUR website! y=8 y int (0,8) no slope, horizontal line

Graphs/463813: Hi! I was wondering if someone would be able to help me with this problem? I have been having a hard time grasping the graphs in this chapter. Thank you!!!! :) Write the slope-intercept equation for the line containing the given pair of points. (6,8) and (3,5) 1 solutions Answer 317705 by rfer(12657)   on 2011-06-23 10:57:19 (Show Source): You can put this solution on YOUR website! m=(5-8)/(3-6) m=-3/-3 m=1 ============= y=mx+b 5=1*3+b b=2 ============= y=x+2

Linear-systems/463586: determin the equasion of a line tha passes through (6,18) and (-12,3) 1 solutions Answer 317652 by rfer(12657)   on 2011-06-22 20:20:54 (Show Source): You can put this solution on YOUR website! m=(3-18)/(-12-6) m=-15/-18 m=5/6 --------------- y=mx+b 3=5/6*-12+b 3=-10+b b=-13 --------------- y=5/6x-13

Travel_Word_Problems/463607: jane sold 125 boxes of girl scout cookies.Thin mints cost $3.00 and shortbread cookies cost $3.25.In all, $388.50 worth of boxes were sold.How many of each kin were sold? ___ boxes of thin mints ___ boxes of shortbread 1 solutions Answer 317650 by rfer(12657)   on 2011-06-22 20:16:50 (Show Source): You can put this solution on YOUR website! m+s=125 s=125-m 3m+3.25s=388.50 3m+3.25(125-m)=388.50 3m+406.25-3.25m=388.50 -0.25m=-17.75 m=71 s=125-71=54

Volume/463643: how many gallons would be in an area 4 ft tallx4 feet widex15 feet long 1 solutions Answer 317647 by rfer(12657)   on 2011-06-22 20:11:44 (Show Source): You can put this solution on YOUR website! 240 cu ft 240*7.5=1800 gal

Geometry_Word_Problems/463624: How much greater is the area of a square that has one side equal to 4 feet than a rectangle that measures 3 feet long and 2 feet wide? 1 solutions Answer 317644 by rfer(12657)   on 2011-06-22 20:05:12 (Show Source): You can put this solution on YOUR website! square A=4^2 A=16 rectangle A=3*2 A=6 difference 16-6=10 sq ft more in square

Quadratic_Equations/463628: I am stuck on this problem, any help would be greatly appreciated. Given a rectangle with a fixed perimeter of 372 feet, what dimensions would yield the maximum area? What is the maximum area? 1 solutions Answer 317643 by rfer(12657)   on 2011-06-22 20:02:47 (Show Source): You can put this solution on YOUR website! a square is max 372/4=93 ft per side A=93^2 A=8649 sq ft

Travel_Word_Problems/463645: How far would a person travel in 4 hours and 20 minutes at 55 miles per hour? 1 solutions Answer 317641 by rfer(12657)   on 2011-06-22 20:00:39 (Show Source): You can put this solution on YOUR website! D=55*4.333 D=238.3 miles

Angles/463664: what are two supplementary angles such that the measure of the first angle is 46 degrees less than three times the measure of the second ? 1 solutions Answer 317639 by rfer(12657)   on 2011-06-22 19:58:33 (Show Source): You can put this solution on YOUR website! 3x-46+x=180 4x=226 x=56.5 3x-46=123.5

real-numbers/463469: 10 - 5/6x = -5/6 + 10 1 solutions Answer 317566 by rfer(12657)   on 2011-06-22 12:16:43 (Show Source): You can put this solution on YOUR website! x=1

Surface-area/463480: A cube has an edge measuring 7 in. What is the surface area of the cube? 1 solutions Answer 317565 by rfer(12657)   on 2011-06-22 12:15:36 (Show Source): You can put this solution on YOUR website! 7*7*6=294 sq in

Finance/463490: Easy Money Inc. charges 22% simple interest (annually) for a 3-year, $1000 loan. Find the interest for 6 months. 1 solutions Answer 317564 by rfer(12657)   on 2011-06-22 12:13:21 (Show Source): You can put this solution on YOUR website! I=1000*0.22*.5 I=$110

Equations/463485: 4(x+2)=28 1 solutions Answer 317562 by rfer(12657)   on 2011-06-22 12:11:38 (Show Source): You can put this solution on YOUR website! 4x+8=28 4x=20 x=5

Word_Problems_With_Coins/463498: what is the value of six dimes and eight pennies 1 solutions Answer 317561 by rfer(12657)   on 2011-06-22 12:10:23 (Show Source): You can put this solution on YOUR website! $0.68

Travel_Word_Problems/463496: Calculate the average speed of a car that has traveled 15 km in 3.5 hours 1 solutions Answer 317560 by rfer(12657)   on 2011-06-22 12:09:36 (Show Source): You can put this solution on YOUR website! r=15/3.5 r=4.3 kph

Graphs/463513: -6x +2>5 1 solutions Answer 317557 by rfer(12657)   on 2011-06-22 12:04:55 (Show Source): You can put this solution on YOUR website! -6x > -3 x < 1/2

Miscellaneous_Word_Problems/463516: I really appreciate your help. A hardware supplier manufactures three kinds of clamps, types A, B,and C. Production restrictions force it to make 10 more type C clamps than the total of the other types and three times as many B clamps as type A clamps. The shop must produce 330 clamps per day. How many of each type are made per day? A clamps B clamps C clamps 1 solutions Answer 317556 by rfer(12657)   on 2011-06-22 12:03:31 (Show Source): You can put this solution on YOUR website! x+3x+(x+3x)+10=330 8x=320 x=40 type A 3x=120 type B 4x+10=170 type C

Numbers_Word_Problems/463295: if five times a number is added to three times the number the result is the sum of seven times the number and nine 1 solutions Answer 317489 by rfer(12657)   on 2011-06-21 21:57:55 (Show Source): You can put this solution on YOUR website! 5x+3x=7(x+9) 8x=7x+63 8x-7x=63 x=63

Travel_Word_Problems/463349: two cars leave a town a the same time. one travels east at 50 miles per hour. the other travels west at 55 miles per hour. in how many hours will they be 315 miles apart? 1 solutions Answer 317488 by rfer(12657)   on 2011-06-21 21:55:01 (Show Source): You can put this solution on YOUR website! moving apart at 105mph 315/105=3 hrs

Triangles/463242: The ratio of the lengths of the legs of a right triangle is 3:4. If the hypotenuse is 20 cm, find the length of the longer leg. 1 solutions Answer 317466 by rfer(12657)   on 2011-06-21 20:40:19 (Show Source): You can put this solution on YOUR website! 12, 16, 20 triangle

Triangles/463245: Find the angle equal to 3/7 of its compliment. 1 solutions Answer 317462 by rfer(12657)   on 2011-06-21 20:36:11 (Show Source): You can put this solution on YOUR website! x+3/7x=90 1 3/7x=90 x=90/1 3/7 x=90/10/7 x=90*7/10 x=63 -------------- 90-63=27 degrees

Problems-with-consecutive-odd-even-integers/463249: Write the slope-intercept equation for the line that passes through (-4, -8) and (-3, -2) Can some one help me with this please 1 solutions Answer 317459 by rfer(12657)   on 2011-06-21 20:32:59 (Show Source): You can put this solution on YOUR website! slope m=(-2--8)/(-3--4) m=6/1 m=6 ------------------ y=mx+b -2=6*-3+b -2=-18+b b=16 ------------- y=6x+16

Graphs/463314: 1.y-1/2x=3 Find the y- and x-intercept for the equation. then graph the equation. 2.x=7-y 3.12y-3x=-9 1 solutions Answer 317455 by rfer(12657)   on 2011-06-21 20:27:36 (Show Source): You can put this solution on YOUR website! 1) y=1/2x+3 y int=(0,3) x int=(-1.5,0)

Polynomials-and-rational-expressions/463290: find the slope and the y-intercept of the line, x-2y=6 1 solutions Answer 317451 by rfer(12657)   on 2011-06-21 20:25:19 (Show Source): You can put this solution on YOUR website! -2y=-x+6 y=1/2x-3 slope m=1/2 y int b=-3 (0,-3)

Miscellaneous_Word_Problems/463308: After taking away 10% from X, I get 3,330. What is number X and what was the value of the 10%? 1 solutions Answer 317449 by rfer(12657)   on 2011-06-21 20:22:25 (Show Source): You can put this solution on YOUR website! 3330/0.9=3700 10%=370