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
Miscellaneous_Word_Problems/164709: A batter in a baseball game drops a bunt down the first-base line. It rolls 42ft at an angle of 36 degrees with the base path. The pitcher's mound is 60.5ft from home plate: How far must the pitcher travel to pick up the ball? Answer to the nearest foot. Note a baseball field is a square.
I drew the field and the triangle within the square, but i dont think my picture is correct. i came up with 36.23 ft; that xoesnt seem correct to me. Please help 1 solutions
Answer 121385 by edjones(7569) on 2008-10-29 18:08:30 (Show Source):
You can put this solution on YOUR website!We have 2 sides of a triangle, 60.5 and 42. The angle between them is 45-36=9 deg. SAS triangle.
a^2=b^2+c^2-2bc*cosA
a^2=60.5^2+42^2-(2*60.5*42*cos(9)
=3660.25+1764-(5082*.987688)
=5424.25-5019.43
=404.818
a=sqrt(404.818)
=20.1201
Answer 20 ft.
.
Ed
|
test/164706: This question is from textbook
0.2y^2+0.03y=0.02 1 solutions
Answer 121383 by edjones(7569) on 2008-10-29 17:38:14 (Show Source):
You can put this solution on YOUR website!0.2y^2+0.03y=0.02
20y^2+3y=2 multiply each side by 100
20y^2+3y-2=0
20*-2=-40. What 2 factors of -40 add up to 3? Ans 8 & -5.
20y^2-5y+8y-2=0
5y(4y-1)+2(4y-1)=0 Factoring by grouping.
(5y+2)(4y-1)=0
5y=-2, 4y=1
y=-2/5, y=1/4
.
Ed
|
Equations/164710: This question is from textbook
can someone help me with this two question.
Classify the function as a linear, quadratic, or exponential.
1. f(x) = -5x - 4
2. f(x) = (x - 5)(x + 4) 1 solutions
Answer 121378 by edjones(7569) on 2008-10-29 17:23:56 (Show Source):
You can put this solution on YOUR website!1. linear because a graph of f(x) is a straight line and it is of the 1st degree.
2. quadratic because it is a polynomial equation of the 2nd degree. Its graph is a parabola.
f(x)=x^2-x-20
.
Ed
.

.
|
Miscellaneous_Word_Problems/163802: Three workers set out to plaster a ceiling. One can do the job alone in 2 hours, one in three hours and the last in 4 hours how long does it take them together to plaster the ceiling? 1 solutions
Answer 120668 by edjones(7569) on 2008-10-24 01:24:29 (Show Source):
You can put this solution on YOUR website!One can do 1/2 the job in 1 hr, another 1/3 and another 1/4 the job in 1 hr.
1/2 + 1/3 + 1/4
=6/12 + 4/12 + 3/12
=13/12 of the job in 1 hr together
12/13 of an hour to do the job working together.
.
Ed
|
Miscellaneous_Word_Problems/163803: one pipe fills a tank in 50 minutes another pipe in 75 how long does it take for both pipes together to fill a tanks?
1 solutions
Answer 120666 by edjones(7569) on 2008-10-24 01:03:13 (Show Source):
You can put this solution on YOUR website!One pipe does 1/50 of the job in 1 minute.
the other pipe doe 1/75 in 1 minute
1/50 + 1/75
=3/150 + 2/150 = 5/150 = 1/30 of the job in 1 minute.
So the tank will be filled in 30 minutes using both pipes.
.
Ed
|
Permutations/163614: Determine the number of different three letter "words" that can be formed using the letters from the word "ARRANGE" 1 solutions
Answer 120530 by edjones(7569) on 2008-10-23 01:02:17 (Show Source):
You can put this solution on YOUR website!1st use each letter only once in the 3 letter word:
5P3=5!/(5-3)!=(5*4*3*2)/2=60
2nd use both double letters with one other letter. rrn rnr nrr There are 3 permutations for each of the 4 single letters=12 There are 2 sets of double letters so 24 are the possible permutations.
60+24=84 "words" altogether.
.
Ed
|
Probability-and-statistics/163450: What's the probability that a sum of 7 or 11 appears at least twice, if the a pair of fair dice are tossed 3 times. 1 solutions
Answer 120416 by edjones(7569) on 2008-10-22 01:47:00 (Show Source):
You can put this solution on YOUR website!The probability of 11 on one roll is 2/36
The probability of 7 on one roll is 6/36
The probability of 7 or 11 on one roll is 8/36=2/9
(a+b)^3=a^3+3a^2b+3ab^2+b^3
Let a=2/9 and b=7/9
We are only interested in the 1st 2 terms:
(2/9)^3+3(2/9)^2(7/9)=.1262 answer.
.
Ed
|
Linear_Equations_And_Systems_Word_Problems/163453: Can you help me solve this problem: A repairman purchased some washing machine motors for a total of $224. When the unit cost decreased by $4, he was able to buy one extra motor for the same total price. How many motors did he buy originally? 1 solutions
Answer 120415 by edjones(7569) on 2008-10-22 01:11:13 (Show Source):
You can put this solution on YOUR website!Let n=number of motors & u=unit cost
A) n*u=224
B) (n+1)*(u-4)=224
.
A) u=224/n
B)
(n+1)*(224/n -4)=224
(n+1)((224-4n)/n)=224 LCD of 224/n -4
(n+1)(224-4n)=224n multiply each side by n to eliminate the fraction.
-4n^2+220n+224=224n
n^2-55n-56=-56n divide each side by -4
n^2+n-56=0
(n+8)(n-7)=0
n=7 motors at $32
8 motors at $28
.
Ed
|
Linear-equations/163243: Debbie is making apple dumplings. They have to be made from 6 inch square pieces of dough. In order to make 6 dumplings, what is the formula or equation to determine the size of the rectangle of dough?
1 solutions
Answer 120305 by edjones(7569) on 2008-10-21 03:06:04 (Show Source):
You can put this solution on YOUR website!6 inch square pieces are squares with each side 6". The area of each square is 6^2=36 in^2
A 36" by 6" rectangle of dough would allow the cutting out of six 6" square pieces of dough.
.
Ed
|
Proportions/163190: write as an equation that represents the relationship between the given variables. Use k as the variation constant.
F varies jointly as h and inversely as the square of r 1 solutions
Answer 120301 by edjones(7569) on 2008-10-21 02:07:22 (Show Source):
|
test/163276: please help me evaluate 1)3x^0 2)(3x)^0.
are the results different? Why or why not are they different? 1 solutions
Answer 120300 by edjones(7569) on 2008-10-21 02:04:09 (Show Source):
|
Average/163277: the average of four numbers is 638.4 the first four numbers are 216 159.8 and 301.25 Find the fourth number. 1 solutions
Answer 120298 by edjones(7569) on 2008-10-21 02:01:27 (Show Source):
|
Inequalities/163052: can someone help me with this problem please
Solve the inequality.
x^2 - 1.01x - 83.19 < 0
(Give approximations rounded to the nearest hundredth.)
a. (-infinity, -8.63) U (9.64, infinity)
b. (9.64, -8.63)
c. (-infinity, -9.64) U (8.63, infinity)
d. (-9.64, 8.63) 1 solutions
Answer 120163 by edjones(7569) on 2008-10-20 02:48:54 (Show Source):
You can put this solution on YOUR website!x^2 - 1.01x - 83.19 < 0
Start with the equality x^2 - 1.01x - 83.19 = 0
x=-8.62982, x=9.63982 (quadratic formula)
These 2 numbers are inflection points.
We can select numbers below -8.7, between the 2 numbers and above 9.7 for x and see what sign y has.
x=-10 then x^2 - 1.01x - 83.19=26.91
x=0 then x^2 - 1.01x - 83.19=-83.91
x=10 then x^2 - 1.01x - 83.19=6.71
(-8.62, 9.64) Answer
.
Ed
.
|
|