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 'edjones'

edjones answered: 7568 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, >>Next

Angles/262578: I have a supplementary angle with measurements (5x-18) and (4x+7) find the value of x
1 solutions

Answer 193459 by edjones(7569) About Me  on 2010-01-28 23:53:28 (Show Source):
You can put this solution on YOUR website!
(5x-18)+(4x+7)=180
9x-11=180
9x=191
x=191/9
180-x=1429/9
.
Ed


Polynomials-and-rational-expressions/262586: Please help me. It's multiplying polynomials:
%28-2r%5E3s%5E4%29%286r%5E2s%29.
1 solutions

Answer 193458 by edjones(7569) About Me  on 2010-01-28 23:43:58 (Show Source):
You can put this solution on YOUR website!
-12r^5s^5 add exponents


Probability-and-statistics/262590: x^2-8x+11=0 Solve the equation by completing the square.
1 solutions

Answer 193457 by edjones(7569) About Me  on 2010-01-28 23:41:37 (Show Source):
You can put this solution on YOUR website!
x^2-8x+11=0
x^2-8x =-11
x^2-8x+16=-11+16
(x-4)^2=5
x-4=+-sqrt(5)
x=4+sqrt(5), x=4-sqrt(5)
.
Ed


Rational-functions/261554: 8.5 x 2/5
1 solutions

Answer 192779 by edjones(7569) About Me  on 2010-01-27 00:49:57 (Show Source):
You can put this solution on YOUR website!
8.5 x 2/5
=17/5
.
Ed


Rectangles/261562: A Rectangle has a diagonal of 2 and a length of square root of 3.Find its width
1 solutions

Answer 192778 by edjones(7569) About Me  on 2010-01-27 00:47:56 (Show Source):
You can put this solution on YOUR website!
There is a right triangle.
a^2+b^2=c^2
sqrt(3)^2+b^2=2^2
3+b^2=4
b^2=1
b=1 width
.
Ed


Age_Word_Problems/261590: Anita has 2 sisters and 3 bros.the mean of all their ages is 6. what will their mean age be 10 years from now?20 years from now?
1 solutions

Answer 192776 by edjones(7569) About Me  on 2010-01-27 00:42:23 (Show Source):
You can put this solution on YOUR website!
10 years from now 16
20 years from now 26


Inequalities/261591: how do you solve 2|x|-4>14
1 solutions

Answer 192775 by edjones(7569) About Me  on 2010-01-27 00:40:55 (Show Source):
You can put this solution on YOUR website!
2|x|-4>14
2|x|>18
|x|>9
.
x>9
x<-9
.
Ed


Permutations/261634: A basketball team has 12 players. There are 5 di fferent positions on
a basketball team. A starting lineup consists of 5 players, each assigned
to one of the 5 positions. How many di fferent ways can a coach select a
starting lineup?
1 solutions

Answer 192774 by edjones(7569) About Me  on 2010-01-27 00:34:14 (Show Source):
You can put this solution on YOUR website!
nCr=n!/((n-r)!r!) combination of n things taken r at a time.
=12C5
=792
.
Ed


logarithm/261611: ln 40 + 2 ln .5 + ln x
1 solutions

Answer 192772 by edjones(7569) About Me  on 2010-01-27 00:30:22 (Show Source):
You can put this solution on YOUR website!
ln 40 + 2 ln .5 + ln x
=ln(40*.5^2*x)
=ln(10x)


Problems-with-consecutive-odd-even-integers/261658: The sum of three even consecutive integers if the first integer is y
1 solutions

Answer 192770 by edjones(7569) About Me  on 2010-01-27 00:26:38 (Show Source):
You can put this solution on YOUR website!
y+y+2+y+4=3y+6


Functions/261630: how do you find the domain of 2|4x-3|?
1 solutions

Answer 192769 by edjones(7569) About Me  on 2010-01-27 00:24:54 (Show Source):
You can put this solution on YOUR website!
all real numbers


Functions/261633: how do you find the domain of x^3 + x^2?
1 solutions

Answer 192768 by edjones(7569) About Me  on 2010-01-27 00:21:24 (Show Source):
You can put this solution on YOUR website!
all real numbers


Numbers_Word_Problems/261645: for how many n is the set ( 1,2,3....100) is the tens digit of n(squared) odd?
1 solutions

Answer 192767 by edjones(7569) About Me  on 2010-01-27 00:17:49 (Show Source):


Probability-and-statistics/260716: If a game were "fair," the payoff on a bet would be the same as the odds for the event. In one game, the odds for winning are 1:13. If the game were "fair," what would the payoff be for a $5 bet? Of course, game in casinos are designed to make a profit for the casino investors. Supposing the casino makes the payoff at 1:11 odds, what profit does the casino make on your winning bet?
1 solutions

Answer 192074 by edjones(7569) About Me  on 2010-01-25 11:19:55 (Show Source):
You can put this solution on YOUR website!
1-13 means that out of every 14 events the bettor loses 13 $1 bets and wins one payoff of $13.
If the payoff is 11 the bettor loses 13 $1 bets and wins 1 payoff of $11 for a net loss of $2.
2/14=1/7= 14 2/7% profit the casino makes.
.
Ed


Probability-and-statistics/260717: Suppose you are playing a game of chance. If you bet $5 on a certain event, you will collect $200 (including your $5 bet) if you win. find the odds used for determining the payoff?
1 solutions

Answer 192068 by edjones(7569) About Me  on 2010-01-25 11:06:18 (Show Source):
You can put this solution on YOUR website!
195/5=39
39 to 1 are the odds against winning. You lose 39*$5=195 and you win $195 once.
.
Ed


Triangles/260312: i have an isosceles triangle. One angle has 3x and the other angle has (x+50).
How to find the third angle
1 solutions

Answer 191738 by edjones(7569) About Me  on 2010-01-24 12:54:10 (Show Source):
You can put this solution on YOUR website!
Are the 2 given angles equal?


Parallelograms/260283: The diagonals of a rhombus have lengths of 12 centimeters and 16 centimeters. What is the length of one side of the rhombus?
1 solutions

Answer 191735 by edjones(7569) About Me  on 2010-01-24 12:49:25 (Show Source):
You can put this solution on YOUR website!
The diagonals of a rhombus form right angles when they intersect. A right triangle is formed who's hypotenuse is a side of the rhombus.
16^2+12^2
=256+144
=400
sqrt(400)=20 cm
.
Ed


Quadratic_Equations/260286: i don't really understand the nature of roots in a quadratic function. it says: for what values of k does kx^2-2x+3=0 have two different real roots? i'm not sure what to plug in or how to continue on from here...
1 solutions

Answer 191732 by edjones(7569) About Me  on 2010-01-24 12:44:28 (Show Source):
You can put this solution on YOUR website!
kx^2-2x+3=0
b^2-4ac=discriminant. If it's >0 then the roots are real and different
4-12k>0
-12k>-4
k<1/3
.
Ed


Circles/260303: Okay. So how do you find the area of a semi-circle if you already have the perimeter? I am solving a problem where the perimeter is 20 and it wants me to find the area of the semi circle. plz help me out!
Thankss!
1 solutions

Answer 191730 by edjones(7569) About Me  on 2010-01-24 12:27:56 (Show Source):
You can put this solution on YOUR website!
The perimeter of a semi-circle is pi*d/2 + d
The perimeter has 2 parts: the circular part which is 1/2 the circumference of a circle and a flat part which is the diameter of the circle.
pi*d/2 + d=20
pi*d+2d=40
d(pi+2)=40
d=40/(pi+2)
r=20/(pi+2)
.
A=(pi*r^2)/2
=pi*(20/(pi+2))^2/2
=pi*(400/(pi+2)^2)*1/2
=200pi/(pi+2)^2 or 23.77
.
Ed


Geometry_Word_Problems/260201: 16. The length of the hypotenuse of a right triangle exceeds the length of the base by 2 cm and exceeds, twice the length of the altitude by 1 cm. Find the length of each side of the triangle.
1 solutions

Answer 191691 by edjones(7569) About Me  on 2010-01-24 10:06:11 (Show Source):
You can put this solution on YOUR website!
b+2=c
b=c-2
.
2a+1=c
2a=c-1
a=(c-1)/2
.
a^2+b^2=c^2
((c-1)/2)^2+(c-2)^2=c^2
(c^2-2c+1)/4 + c^2-4c+4=c^2
c^2-2c+1+4(c^2-4c+4)=4c^2
c^2-2c+1+4c^2-16c+16=4c^2
c^2-18c+17=0
(c-17)(c-1)=0
c=17
b=15
a=8
.
Ed


real-numbers/260199: Is -3 is a Rational and a Real Number?
1 solutions

Answer 191684 by edjones(7569) About Me  on 2010-01-24 09:46:03 (Show Source):
You can put this solution on YOUR website!
all integers are rational and real.


Average/260205: The average(arithmetic mean) of nine numbers is 9. When a tenth number is added the average of the ten numbers is also 9. What is the tenth number ?
a) 9/10 b) 10/9 c) 9 d) 10
1 solutions

Answer 191679 by edjones(7569) About Me  on 2010-01-24 09:41:21 (Show Source):


Square-cubic-other-roots/260209: cuberoot(54)
1 solutions

Answer 191678 by edjones(7569) About Me  on 2010-01-24 09:40:43 (Show Source):
You can put this solution on YOUR website!
Factor(54)=2,3,3,3
root%283%2C54%29=3root%283%2C2%29
.
Ed


Polynomials-and-rational-expressions/260238: Multiplying Rational Numbers:
3/4 * 8/21 =
1 solutions

Answer 191661 by edjones(7569) About Me  on 2010-01-24 08:51:57 (Show Source):
You can put this solution on YOUR website!
3/4 * 8/21
=24/84=6/21=2/7


Percentage-and-ratio-word-problems/260226: A water storage tank is 1/3 full of water. Fifteen gallons of water are added to the tank.The tank is now 1/2 full. How many gallons of water will the tank hold?
1 solutions

Answer 191660 by edjones(7569) About Me  on 2010-01-24 08:48:21 (Show Source):
You can put this solution on YOUR website!
Let x=capacity of tank.
x/3+15=x/2
2x+90=3x
x=90 gal
.
Ed


Probability-and-statistics/260162: In a small class of 10 students, 3 did not do their homework. The professor selects half of the class to present solutions to do homework problems on the board, and records how many of those selected did not do their homework.
A. give a probability distribution
b. sketch its histogram
c. find expected value
1 solutions

Answer 191640 by edjones(7569) About Me  on 2010-01-24 02:04:11 (Show Source):
You can put this solution on YOUR website!
nCr=combination of n things taken r at a time
.
10C5=252 the denominator for all of these
probability distribution:
all 5 did their homework 7C5/252=21/252=.0833
4 did, 1 didn't. (7C4 * 3C1)/252=35*3/252=.4167
3did, 2 didn't. (7C3 * 3C2)/252=35*3/252=.4167
2 did, 3 didn't (7C2 * 3C3)/252=21/252=.0833
Make the histogram from the above figures.
.
The expectation is that 1 or 2 of the selected 5 didn't do their homework
.
Ed


Matrices-and-determiminant/260052: how are determinants used in the "real world"?
1 solutions

Answer 191545 by edjones(7569) About Me  on 2010-01-23 18:01:41 (Show Source):
You can put this solution on YOUR website!
If it is negative then the zeros of the quadratic are not real numbers.


Linear-equations/260098: What is the x intercept for y= -3/4x+5. I have (6.75,0)which is wrong?
1 solutions

Answer 191544 by edjones(7569) About Me  on 2010-01-23 17:55:20 (Show Source):
You can put this solution on YOUR website!
y= -3/4x+5
(-3/4)x+5=0
(-3/4)x=-5
x=-5 / -3/4
x=-5 * -4/3
=20/3 you weren't wrong by much.
.
Ed


absolute-value/259961: If - | -h | = - | g - 4 | and g = -6, then what is the value of h?

(A) -10 (B) -2 (C) 2 (D) 6 (E) 10
1 solutions

Answer 191539 by edjones(7569) About Me  on 2010-01-23 17:46:47 (Show Source):
You can put this solution on YOUR website!
- | -h | = - | g - 4 |
- | -h | = - | -6 - 4 |
|-h|=|-10| multiply each side by -1.
h=-10, h=10
.
Ed


Exponents/259963: If 4x + 4y = 20 and 8x^-1/2 = 4^-1, then what is the value of y?
1 solutions

Answer 191534 by edjones(7569) About Me  on 2010-01-23 17:32:06 (Show Source):
You can put this solution on YOUR website!
8x^-1/2 = 4^-1
8/sqrt(x)=1/4
sqrt(x)=32 multiply each side by 4sqrt(x)
x=32^2
=1024
.
Ed


Quadratic_Equations/259995: solve by completing the square: x^2+7/2x=7
1 solutions

Answer 191532 by edjones(7569) About Me  on 2010-01-23 17:24:55 (Show Source):
You can put this solution on YOUR website!
x^2+(7/2)x=7 I assume that this is the problem.
x^2+(7/2)x+49/16=7 + 49/16
(4x+7)^2/16=161/16
(4x+7)/4=+-sqrt(161)/4
4x+7=+-sqrt(161)
4x=-7+-sqrt(161)
x=(-7+-sqrt(161))/4
.
Ed