New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'nerdybill'
nerdybill answered: 6946 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, >>Next
Miscellaneous_Word_Problems/469478: a pipe can fill a pool in 8 hours another pipe fill in 12 hours. if both pipes are applied to fill pool than how many hours it will take??? 1 solutions
Answer 322119 by nerdybill(6948) on 2011-07-12 09:39:25 (Show Source):
You can put this solution on YOUR website!a pipe can fill a pool in 8 hours another pipe fill in 12 hours. if both pipes are applied to fill pool than how many hours it will take???
.
Let x = time (hrs) it takes for both
then
x(1/8 + 1/12)= 1
multiplying both sides by 96:
x(12 + 8)= 96
x(20)= 96
x = 4.8 hours
or
x = 4 hours and 48 minutes
|
Rate-of-work-word-problems/469308: can someone help me plssssssssss :)?
it takes carolyn 4 hr to type a final exam. it takes Elise 3 hr to do the same job. How long would it take them, working together, to do the typing? 1 solutions
Answer 321958 by nerdybill(6948) on 2011-07-11 17:40:48 (Show Source):
You can put this solution on YOUR website!it takes carolyn 4 hr to type a final exam. it takes Elise 3 hr to do the same job. How long would it take them, working together, to do the typing?
.
Let x = time (hours) it takes for both
then
x(1/4 + 1/3) = 1
multiplying both sides by 12:
x(3 + 4) = 12
x(7) = 12
x = 12/7
x = 1.7 hours
or
x = 1 hour and 43 minutes
|
Quadratic_Equations/468702: Solve.
9x^4-18x^2+5=0
Would someone please help me solve this problem. I come up with various answers, and I know that there is only one set of answers. Thank you very much. 1 solutions
Answer 321579 by nerdybill(6948) on 2011-07-09 18:05:48 (Show Source):
You can put this solution on YOUR website!9x^4-18x^2+5=0
rewrite as:
9x^4-15x^2-3x^2+5=0
group terms:
(9x^4-15x^2)-(3x^2-5)=0
3x^2(3x^2-5)-(3x^2-5)=0
(3x^2-5)(3x^2-1)=0
.
x = {sqrt(5/3), sqrt(1/3)}
rationalize denominators:
x = {  ,  }
|
Exponential-and-logarithmic-functions/468582: Solve the problem.
An-Mei owns a business making and selling jackets. She has a fixed cost of $1190. It costs $92 to produce each jacket. The selling price is $109 per jacket. Let x represent the number of jackets produced and sold and write the cost function, C, and revenue function, R.
1 solutions
Answer 321529 by nerdybill(6948) on 2011-07-09 11:37:37 (Show Source):
You can put this solution on YOUR website!An-Mei owns a business making and selling jackets. She has a fixed cost of $1190. It costs $92 to produce each jacket. The selling price is $109 per jacket. Let x represent the number of jackets produced and sold and write the cost function, C, and revenue function, R.
.
Cost Function:
C(x) = 92x + 1190
.
Revenue function:
R(x) = 109x - (92x + 1190)
R(x) = 17x - 1190
|
test/468580: Use the given conditions to write an equation for the lone in point-slope form slope=6/7, passing through (7,3) 1 solutions
Answer 321528 by nerdybill(6948) on 2011-07-09 11:30:39 (Show Source):
You can put this solution on YOUR website! Use the given conditions to write an equation for the lone in point-slope form slope=6/7, passing through (7,3)
.
"Point-slope" form is:
y - y1 = m(x - x1)
plugging in the given information:
y - 3 = (6/7)(x - 7)
|
Graphs/468407: Write the slope intercept equation for the line that passes through (-9,-5) and has a slope of 2/9. 1 solutions
Answer 321394 by nerdybill(6948) on 2011-07-08 17:14:29 (Show Source):
You can put this solution on YOUR website!Write the slope intercept equation for the line that passes through (-9,-5) and has a slope of 2/9.
.
use "point-slope" form:
y - y1 = m(x - x1)
y - (-5) = (2/9)(x - (-9))
y + 5 = (2/9)(x + 9)
y + 5 = (2/9)x + 2
y = (2/9)x + 2 - 5
y = (2/9)x - 3
|
test/468387: Please help me find the domain of this function  1 solutions
Answer 321383 by nerdybill(6948) on 2011-07-08 15:45:59 (Show Source):
You can put this solution on YOUR website!The domain specifies all values that makes sense for 'x'.
You only have to eliminate numbers that drives the denominator to zero.
x^2+x-6 = 0
(x-3)(x+2) = 0
x = {-2,3} (these are the numbers that must be eliminated)
.
thus the domain (in interval notation) is
(-oo, -2) U (-2,3) U (3, +oo)
where
oo is infinity
|
test/468231: A builder is building a rectangular deck with dimensions of 16 feet by 30 feet. To ensure that the sides form 90 degree angles, what should each diagonal measure? (A). 30ft. (B). 34ft. (C). 46ft. (D). 16ft 1 solutions
Answer 321311 by nerdybill(6948) on 2011-07-08 10:32:20 (Show Source):
|
Angles/468255: the supplement of an angle is 6 times its complement. Find an angle ?
1 solutions
Answer 321289 by nerdybill(6948) on 2011-07-08 08:50:43 (Show Source):
You can put this solution on YOUR website!the supplement of an angle is 6 times its complement. Find an angle ?
.
Let x = the angle
then
90-x = the complement
180-x = the supplement
.
180-x = 6(90-x)
180-x = 540-6x
180+5x = 540
5x = 360
x = 72 degrees
|
Problems-with-consecutive-odd-even-integers/467653: I am thinking of two consecutive even integers. The sum of their squares is 340. what are the integers? PLEASE HELP! 1 solutions
Answer 320886 by nerdybill(6948) on 2011-07-06 14:14:42 (Show Source):
You can put this solution on YOUR website!I am thinking of two consecutive even integers. The sum of their squares is 340. what are the integers?
.
Let x = first of two consecutive even integers
then
x+2 = second even integer
.
x^2 + (x+2)^2 = 340
x^2 + (x+2)(x+2) = 340
x^2 + x^2+4x+4 = 340
2x^2+4x+4 = 340
x^2+2x+2 = 170
x^2+2x-168 = 0
(x+14)(x-12) = 0
x = {-14, 12}
.
solution:
the two integers are
12 and 14
or
-12 and -14
|
Miscellaneous_Word_Problems/467569: A 2005 Honda minivan can travel 240 miles in the city on 4 gallons of gas. Find the amount of gas required for 360 miles of city driving. (hint: use a proportion). 1 solutions
Answer 320861 by nerdybill(6948) on 2011-07-06 12:40:06 (Show Source):
You can put this solution on YOUR website!A 2005 Honda minivan can travel 240 miles in the city on 4 gallons of gas. Find the amount of gas required for 360 miles of city driving. (hint: use a proportion).
.
Let x = amt of gas (gallons) used to drive 360 miles
then
240/4 = 360/x
cross multiplying:
240x = 4(360)
240x = 1440
x = 6 gallons
|
Angles/467561: An angle is equal to eight times its complement. Determine its measure.
Let x be the angle
then
90-x is its complement.
Therefore,x = 8(90-x)
x = 720-8x
x+8x = 720
9x = 720
x = 720/9
x = 80.
1 solutions
Answer 320828 by nerdybill(6948) on 2011-07-06 10:02:05 (Show Source):
You can put this solution on YOUR website!An angle is equal to eight times its complement. Determine its measure.
.
Let x = the angle
then
90-x = complement of angle
.
x = 8(90-x)
x = 720-8x
8x = 720
x = 90 degrees
|
Pythagorean-theorem/466699: the diagonal of a square is 24 centimeter.how long is the side of the square/
1 solutions
Answer 320093 by nerdybill(6948) on 2011-07-03 16:35:41 (Show Source):
You can put this solution on YOUR website!the diagonal of a square is 24 centimeter.how long is the side of the square
.
apply Pythagorean theorem:
Let x = length of side of square
then
x^2 + x^2 = 24
2x^2 = 24
x^2 = 12
x = sqrt(12)
x = sqrt(2*2*3)
x = 2*sqrt(3) centimeters (exact answer)
.
Or, decimal approx:
x = 3.46 centimeters
|
Polynomials-and-rational-expressions/466814: the question states, simpify be removing factors of 1. 9-z/z-9. this is what i got, (z+3)^2. i dont know if it is right so i was asking for some help please. thank you. 1 solutions
Answer 320089 by nerdybill(6948) on 2011-07-03 16:21:59 (Show Source):
You can put this solution on YOUR website!(9-z)/(z-9)
notice if I factor out a -1 from the numerator I get:
-1(-9+z)/(z-9)
then, if I reorder the terms inside the parenthesis:
-1(z-9)/(z-9)
Now, I can cancel like-terms leaving:
-1
|
Graphs/466574: Hello and thank you so much for your help.I got this function 7-6x-x^2=0 it's a parabola that crosses the x-axis on the points -7.0 and 1.0, the vertex it's at the point (-3.0,16). I need to find the equation of the axis of symmetry for this parabola. Thank you again and have a happy 4th of July. 1 solutions
Answer 319891 by nerdybill(6948) on 2011-07-02 15:17:05 (Show Source):
You can put this solution on YOUR website! Hello and thank you so much for your help.I got this function 7-6x-x^2=0 it's a parabola that crosses the x-axis on the points -7.0 and 1.0, the vertex it's at the point (-3.0,16). I need to find the equation of the axis of symmetry for this parabola. Thank you again and have a happy 4th of July.
.
You can derive the axis of symmetry from the vertex and "inspecting" the original equation.
First,
Determine whether it is a "vertical" or a "horizontal" parabola. If your equation has a x^2 term -- it is a "vertical" parabola.
Second,
Once you know this, then you can simply use the x-coordinate of the vertex. So, the axis of symmetry is then
x = -3 (vertical line crossing the x-axis at -3)
.
Note:
the axis of symmetry is also derived by:
-b/(2a)
where
'a' and 'b' are the coefficients of the original equation
|
Probability-and-statistics/466368: there are 9 books 55% of 9 books are out,how many are left? solve this problem using a proportion show all steps.and explain 1 solutions
Answer 319736 by nerdybill(6948) on 2011-07-01 18:47:14 (Show Source):
You can put this solution on YOUR website! there are 9 books 55% of 9 books are out,how many are left? solve this problem using a proportion show all steps.and explain
.
since 55% are out
100-55 = 45% are left
.
Let x = books left
then
x/9 = 45/100 (this is your proportion)
cross multiplying:
100x = 9*45
100x = 405
x = 4.05
since you can't have fractional book, you have to round down:
there are 4 books left
|
|