See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On


   
By Tutor
 | By Problem Number | 

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

Recent problems solved by 'rfer'

rfer answered: 12650 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/500072: the sum of three consecutive integers is 165. what are the integers?
1 solutions

Answer 337974 by rfer(12654) About Me  on 2011-09-18 21:28:36 (Show Source):
You can put this solution on YOUR website!
x+x+1+x+2=165
3x=162
x=54
x+1=55
x+2=56


Angles/500073: 1. Find the measures of two complementary angles,

1 solutions

Answer 337972 by rfer(12654) About Me  on 2011-09-18 21:27:02 (Show Source):
You can put this solution on YOUR website!
need more info.


Trigonometry-basics/500052: how can you convert the measurement 6.2pm to meters
1 solutions

Answer 337971 by rfer(12654) About Me  on 2011-09-18 21:26:26 (Show Source):
You can put this solution on YOUR website!
6.2 picometers=6.2x10-12 meters


Linear-equations/500058: Directions: Write the slope-intercept form of an equation of the line that passes through the givenn point and is parallel to the graph of each equation.
Ex: (-2,5), y= -4x+2
1 solutions

Answer 337970 by rfer(12654) About Me  on 2011-09-18 21:13:42 (Show Source):
You can put this solution on YOUR website!
5=-4*-2=b
5=8+b
5-8=b
b=-3
--------
y=-4x-3


Equations/500054: country A produces about seven times the amount of diamonds in carats produced in country B. if the total produced in both countries is 32,000,000 carats, find the amount produced in each country.
1 solutions

Answer 337969 by rfer(12654) About Me  on 2011-09-18 21:11:41 (Show Source):
You can put this solution on YOUR website!
x+7x=3.2x10^7
8x=3.2x10^7
x=3.2x10^7/8
x=0.4x10^7
x=4x10^6
7x=2.8x10^7
or
x=4,000,000
7x=28,000,000


Graphs/499981: how do i graph 4.5x + 12.5y = 4500 on my TI-83 plus?
1 solutions

Answer 337967 by rfer(12654) About Me  on 2011-09-18 21:07:25 (Show Source):
You can put this solution on YOUR website!
4.5x+12.5y=4500
12.5y=-4.5x+4500
y=-4.5/12.5x+4500/12.5
y=-0.36x+360 enter it this way
---------------
slope m=-0.36
y int b=360
--------------
put the equation in slope/intercept form, then enter in calculator


Expressions-with-variables/500048: What is the equation or formula for the varible specified:
4z+b=2z+c solve for C
1 solutions

Answer 337965 by rfer(12654) About Me  on 2011-09-18 21:01:35 (Show Source):
You can put this solution on YOUR website!
c=(4z+b)-2z
c=2z+b


Rectangles/500034: The perimeter of a rectangle is 62 inches. If the length of the rectangle is 1 inch more than twice the width what are the dimensions of the rectangle?
I need to set up an equation and solve
1 solutions

Answer 337963 by rfer(12654) About Me  on 2011-09-18 20:59:37 (Show Source):
You can put this solution on YOUR website!
2x+2(2x+1)=62
2x+4x+2=62
6x=60
x=10
2x+1=21


Money_Word_Problems/500038: find how much interest $15,000 earned in 2 years in a certificate of deposit paying 9.5% interest compounded quarterly
1 solutions

Answer 337961 by rfer(12654) About Me  on 2011-09-18 20:56:53 (Show Source):
You can put this solution on YOUR website!
A=P(1+0.095/4)^4*2
A=15000(1.02375)^8
A=15000*1.207
A=18098.50
--------
18098.50-15000=$3,098.50


Travel_Word_Problems/500037: If Im driving 65 mph how long will it take me to drive 4 miles.
1 solutions

Answer 337960 by rfer(12654) About Me  on 2011-09-18 20:52:25 (Show Source):
You can put this solution on YOUR website!
t=D/r
t=4/65
t=0.0615 hrs
---------------
60*0.0615=3.7 min


Expressions-with-variables/500028: Hello, my Algebra homework is becoming very difficult for me. May you please help me solve the following problem?
3/n - 1/4 = 1/12 - 5/3
Three over n - one fourth = one over twelve - five over three.
If you have a little extra time may you please, explain the steps on how to do it? Well, thank you for helping me. I really do appreciate it(:
1 solutions

Answer 337958 by rfer(12654) About Me  on 2011-09-18 20:50:24 (Show Source):
You can put this solution on YOUR website!
3/n-1/4=1/12-5/3
3/n=1/12-5/3+1/4
3/n=1/12-20/12+3/12
3/n=-16/12
n=-16/12*3/1
n=48/12
n=4
Don't for get about common denominators.


Functions/500029: Does the table represent a fucton if the input is 5,6,7,8 and the output is 3,4,5,6?
1 solutions

Answer 337956 by rfer(12654) About Me  on 2011-09-18 20:41:39 (Show Source):


Average/499985: 4(x+5)+2x=x+10
1 solutions

Answer 337954 by rfer(12654) About Me  on 2011-09-18 20:40:31 (Show Source):
You can put this solution on YOUR website!
4x+20+2x=x+10
6x-x=10-20
5x=-10
x=-2


Polynomials-and-rational-expressions/500025: 4. Essay; show all work. Add the following polynomials:
(-1/3x^2-1/4x+3/4)+(1/2x^2-1/4x-1/2)
I do not understand how to do this !!!
1 solutions

Answer 337953 by rfer(12654) About Me  on 2011-09-18 20:38:23 (Show Source):
You can put this solution on YOUR website!
combine like terms
-1/3x^2+1/2x^2=-2/6x^2+3/6x^2=1/6^2
-1/4x-1/4x=-2/4x=-1/2x
3/4-1/2=3/4-2/4=1/4
answer
1/6^2-1/2x+1/4


Travel_Word_Problems/500002: If a cylinder 8m high has a volume of 32pi m3, what is its radius?
1 solutions

Answer 337951 by rfer(12654) About Me  on 2011-09-18 20:34:03 (Show Source):
You can put this solution on YOUR website!
V=pir^2h
32pi/8=4pi
sqrt 4=2
2 m = radius


Number-Line/500017: What is the lowest number of a negative on the number line?
1 solutions

Answer 337950 by rfer(12654) About Me  on 2011-09-18 20:29:50 (Show Source):
You can put this solution on YOUR website!
negative infinity


Triangles/500019: If the measure of the third angle of the triangle is 35 degrees more than three times the measure of either of the other two angles, find the measure of each triangle.
1 solutions

Answer 337949 by rfer(12654) About Me  on 2011-09-18 20:28:18 (Show Source):
You can put this solution on YOUR website!
x+x+3x+35=180
5x=180-35
5x=145
x=145/5
x=29 for two
3x+35=122


Equations/500000: lopez spent 1/3 of his vacation money for travel and 2/5 of his vacation money for lodging. He spent $1100 for travel and lodging. What is the total amount of money he spent on his vacation?

1 solutions

Answer 337945 by rfer(12654) About Me  on 2011-09-18 20:23:43 (Show Source):
You can put this solution on YOUR website!
1100/(2/5+1/3)=
1100/(6/15+5/15)=
1100/11/15=
1100*15/11=$1500


Problems-with-consecutive-odd-even-integers/500004: four times the sum of a number and 3
1 solutions

Answer 337944 by rfer(12654) About Me  on 2011-09-18 20:20:14 (Show Source):


Expressions-with-variables/500007: Hi, may you please explain to me how to do this problem?
2/3y + 5/6 = 3/2y
(two over three y)+ (five over six) = (Three over two y)
Do I multiply by three over one one both sides to start off?
Well, Thank you for taking your time to help me with my homework. I really appreciate your help.
1 solutions

Answer 337943 by rfer(12654) About Me  on 2011-09-18 20:18:34 (Show Source):
You can put this solution on YOUR website!
2/3y+5/6=3/2y
5/6=3/2y-2/3y
5/6=9/6y-4/6y
5/6=5/6y
y=(5/6)/(5/6)
y=5/6*6/5
y=30/30
y=1


Average/499914: exactly 830 people took part in a local fund raising eent. The number of adults was 80 more than twice the number of children. If there 278 men, how many women were there?

1 solutions

Answer 337908 by rfer(12654) About Me  on 2011-09-18 17:59:09 (Show Source):
You can put this solution on YOUR website!
x+2x+80=830
3x=830-80
3x=750
x=250 children
----------
830-250=580 adults
----------------
580-278=302 women


Problems-with-consecutive-odd-even-integers/499910: the largest angle of a triangle is 20 degrees more than twice the smallest, and the third angle measures 70 degrees. Find the size of the angles of the triangle.
1 solutions

Answer 337906 by rfer(12654) About Me  on 2011-09-18 17:55:41 (Show Source):
You can put this solution on YOUR website!
x+2x+20+70=180
3x=180-90
3x=90
x=30
2x+20=80


Numeric_Fractions/499846: 1/2+(3/4 / 3/4)-(4/5 * 5/6)=?
1 solutions

Answer 337903 by rfer(12654) About Me  on 2011-09-18 17:52:10 (Show Source):
You can put this solution on YOUR website!
1/2+1-20/30
1/2+1-2/3
3/6+6/6-4/6=5/6


Numeric_Fractions/499903: please help me solve this equation 6 3/22 divided by 7 1/11 =



1 solutions

Answer 337899 by rfer(12654) About Me  on 2011-09-18 17:48:25 (Show Source):
You can put this solution on YOUR website!
(6 3/22)/(7 1/11)
(135/22)/(78/11)
135/22*11/78=1485/1716=45/52


Linear-equations/499899: IF YOU HAVE A X AXIS OF 5 AND Y AXIS OF -8 WHAT IS THE Y INTERCEPT COULD YOU PLEASE SHOW ME WORK SO I CAN UNDERSTAND HOW YOU GET THE Y INTERCEPT??
1 solutions

Answer 337898 by rfer(12654) About Me  on 2011-09-18 17:44:51 (Show Source):
You can put this solution on YOUR website!
From your question, I am not sure all the information is there.
Is it?
(5,-8)
or
(5,0)
(0,-8)
--------------
If it is the bottom, (0,-8) is the y intercept.
Y intercept is when x=0


Numbers_Word_Problems/499865: Twelve is five less than the product of a number and two.
1 solutions

Answer 337897 by rfer(12654) About Me  on 2011-09-18 17:40:14 (Show Source):
You can put this solution on YOUR website!
12+5=2x
17=2x
x=17/2
x=8.5


Linear-systems/499851: is this the same as the section as
Applications of Linear Systems?
Ex: A motel clerk counts his $1 and $10 bills at the end of the day. He finds that he has a total of 74 bills having a combined monetary value of $326. Find the number of bills of each denomination that he has.
let x= the number of $1 bills the clerk has, and y= the number of $10 bills he has
He has 74 bills altogether, so one equation is x+y=74. To find the second equation, the dollar amount in $1 bills plus the dollar amount in $10 bills is $326, so 1x+10y=326.
1 solutions

Answer 337894 by rfer(12654) About Me  on 2011-09-18 17:36:28 (Show Source):
You can put this solution on YOUR website!
x+y=74 y=74-x
---------------
x+10y=326
x+10(74-x)=326
x+740-10x=326
-9x=-414
x=-414/-9
x=46
------------
y=74-46
y=28


Rate-of-work-word-problems/499855: If 12 workers can dig a tunnel in 100 days, how long will it take 20 workers to dig the tunnel?
we have no clue what formula to use or where to start any help will help even if it is just the formula thanks.
1 solutions

Answer 337892 by rfer(12654) About Me  on 2011-09-18 17:30:58 (Show Source):
You can put this solution on YOUR website!
Both sides have to equal.
12*100=20x
1200=20x
x=1200/20
x=60 days


Vectors/499880: Solve the equation to find a formula for d.
F=G m1m2/d^2
1 solutions

Answer 337890 by rfer(12654) About Me  on 2011-09-18 17:25:53 (Show Source):
You can put this solution on YOUR website!
d=sqrt(Gm^1m^2/F)


Expressions-with-variables/499887: I am dividing and simplifying rational expressions.
v^2-9 over 4v+12 / v-3 over 6
so far i have
v^2-9 over 4v+12 * 6/ v-3
1 solutions

Answer 337889 by rfer(12654) About Me  on 2011-09-18 17:23:34 (Show Source):
You can put this solution on YOUR website!
(6v^2-45)/(4v^2-12v+12v-36)
(6v^2-45)/(4v^2-36)=3/2 R9


Angles/499279: Two angles are complementary. The measure of one angle is 21 more than twice the measure of the other angle. Find the measures of the angles.

1 solutions

Answer 337599 by rfer(12654) About Me  on 2011-09-17 16:36:54 (Show Source):
You can put this solution on YOUR website!
x+2x+21=90
3x=90-21
3x=69
x=69/3
x=23
2x+21=67