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edjones answered: 7568 problems
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Polynomials-and-rational-expressions/189441: x/2 - x/9 = 7 1 solutions Answer 142102 by edjones(7569)   on 2009-04-02 23:46:39 (Show Source): You can put this solution on YOUR website! x/2 - x/9 = 7 9x-2x=126 multiply each side by 18 (LCM) to eliminate fractions. 7x=126 x=18 . Ed

Average/189149: ROOT:5-x = x-3 do I first set both sides squared to get rid of the root? this again says check all proposed solutions which I don't understand. 1 solutions Answer 141890 by edjones(7569)   on 2009-04-01 01:27:12 (Show Source): You can put this solution on YOUR website! sqrt(5-x)=x-3 5-x=x^2-6x+9 square each side. x^2-5x+4=0 subtract the left side from the right. (x-4)(x-1)=0 factor x=4, x=1 These are the proposed solutions. Now you have to put them into the original equation and check to see if the solution is a true one or if it is extraneous. . sqrt(5-4)=4-3 sqrt(1)=1 true . sqrt(5-1)=1-3 2=-2 extraneous . Ed

Percentage-and-ratio-word-problems/189141: Q: The ratio of the length of a retangular field to its width is 4:3. The perimeter is 308 meters. What are its dimensions? P = 2l + 2w Please give steps required for solving. Thanks, Blake 1 solutions Answer 141889 by edjones(7569)   on 2009-04-01 01:07:12 (Show Source): You can put this solution on YOUR website! L=4w/3 2L+2w=P 2(4w/3)+2w=308 substitute 4w/3 for L 8w/3 + 2w = 308 8w+6w=924 multiply each side by 3 to eliminate fraction. 14w=924 w=66 L=88 . Ed

Linear_Equations_And_Systems_Word_Problems/188902: A boat took 1 hour and 50 minutes to go 55 km downstream and 3 hours, 40 minutes to return. Find the boats rate in still water and the rate of the current? downstream data: distance=55km; time= (11/6) hr.; rate=d/t= 55/(11/6= 30 kph need to know how 1 hour and 50 minutes changes to 11/6 of an hr? and how does 55/(11/6)= 30? up stream data: distance= 55 km; time= (11/3)hr. rate= d/t= 55/(11/3)=15 kph need to know how 3 hours and 40 minutes = (11/3)of an hour and how does 55/(11/3)=15 kph? 1 solutions Answer 141777 by edjones(7569)   on 2009-03-31 03:02:41 (Show Source): You can put this solution on YOUR website! Let r=speed of boat in still water, c=speed of current, t=time, d=distance rt=d 110(r+c)=55 220(r-c)=55 . 110r+110c=55 220r-220c=55 . 220r+220c=110 multiply the 1st equation by 2 220r-220c==55 --------------add 440r======165 . r=.375 kpm . 110(.375+c)=55 41.25+110c=55 110c=13.75 kpm c=.125 kpm . r=.375*60=22.5 kph c=.125*60=7.5 kph . Ed

Polynomials-and-rational-expressions/188964: factor using GCF 1. m*m-8m*m*m*m*m 2. 3k*k+6k-3 3.w*w*w-4w*w+w-4 4.x*x+6x+8 1 solutions Answer 141776 by edjones(7569)   on 2009-03-31 02:28:28 (Show Source): You can put this solution on YOUR website! 1. m*m-8m*m*m*m*m =m^2-8m^5 =m^2(1-8m^3) =-m^2(8m^3-1) =-m^2(2m-1)(4m^2+2m+1) . 2. 3k*k+6k-3 =3k^2+6k-3 =3(k^2+2k-1) . 3.w*w*w-4w*w+w-4 =w^3-4w^2+w-4 =w^2(w-4)+(w-4) =(w^2+1)(w-4) . 4.x*x+6x+8 x^2+6x+8 (x+4)(x+2) . Ed

Equations/188633: Question: The cost of the telephone call for 8 minutes between two countries is Rs.315 and a 10 minutes call costs rupees 385. Find the cost of first 3 minutes and the rate of each additional minute call. 1 solutions Answer 141563 by edjones(7569)   on 2009-03-29 01:30:32 (Show Source): You can put this solution on YOUR website! 385-315=Rs 70 for 2 min. Each additional min is 70/2=35 35*5=175 cost of 5 additional min. 315-175=Rs 140 cost of the 1st 3 min. . Ed

Quadratic_Equations/188745: I did this problem and somehow came out with such a big answer that it does not seem right can anyone explain how to solve this by simplifying? Thank you. (2b+1)^4 1 solutions Answer 141562 by edjones(7569)   on 2009-03-29 01:16:06 (Show Source): You can put this solution on YOUR website! (2b+1)^4 (2b+1)^2 =4b^2+3b+1 (4b^2+3b+1)^2 =16b^4+32b^3+24b^2+8b+1 . Ed

Permutations/188747: nP2 = 12. Solve for n. 1 solutions Answer 141561 by edjones(7569)   on 2009-03-29 01:08:33 (Show Source): You can put this solution on YOUR website! nP2=12 n!/(n-2)!=12 4*3=12 4*3*2/2=12 (n-2)!=2! n=4 . Ed

Equations/188549: How do you do inverse operations like these because I have trouble in my sixth grade math class??? m over 6.9 (like a fraction) eqauls 0.47 M/6.9 = .47 1 solutions Answer 141374 by edjones(7569)   on 2009-03-26 23:46:41 (Show Source): You can put this solution on YOUR website! This is not an inverse. m/6.9=.47 m=.47*6.9 multiply each side by 6.9 to eliminate the fraction. m=3.243 . Ed

Numbers_Word_Problems/188543: The diagonal of a rectangle measures 15 inches and the length is 3 more than the width. Find the length and width of the rectangle. 1 solutions Answer 141373 by edjones(7569)   on 2009-03-26 23:39:48 (Show Source): You can put this solution on YOUR website! We have a right triangle. The diagonal is the hypotenuse. Let L=w+3 a^2+b^2=c^2 w^2+(w+3)^2=15^2 substitute w+3 for L w^2+w^2+6w+9=225 2w^2+6w-216=0 w^2+3w-108=0 divide each side by 2. (w+12)(w-9)=0 w=9" L=12" . Ed

Numbers_Word_Problems/188545: A square has sides labeled with (2n+3). Write an expression for its area. 1 solutions Answer 141372 by edjones(7569)   on 2009-03-26 23:26:22 (Show Source): You can put this solution on YOUR website! A(square)=s^2 =(2n+3)^2 =4n^2+12n+9 . Ed

Numbers_Word_Problems/188546: The cost, C, of manufacturing x water sprinklers is given by the formula C=x^2-27x-20. Determine the number of water sprinklers manufactured at a cost of $70. 1 solutions Answer 141370 by edjones(7569)   on 2009-03-26 23:22:44 (Show Source): You can put this solution on YOUR website! x^2-27x-20=70 x^2-27x-90=0 (x-30)(x+3)=0 x=30 sprinklers. . Ed

Permutations/188540: Sam had 9 sweaters. If he wore one a day for a week, how many permutations are possible? My math teacher gave me a sheet of permutations to answer at the end of class and without previous knowledge I am having a very difficult time with these questions. I am asking the one that seems the easiest so that I can try to figure out the remaining. My answer is 36 but I'm not sure if its correct or how I should have gotten there. Thank you. 1 solutions Answer 141369 by edjones(7569)   on 2009-03-26 23:16:14 (Show Source): You can put this solution on YOUR website! With permutations the order in which the objects are arrainged is important. nPr Arraingement of r objects selected from a total of n objects. =9P7 =n(n-1)(n-2)*...*(n-r+1) =n!/(n-r)! faster than the line above. =9!/(9-7)! =9!/2! =9*8*7*6*5*4*3 =181440 answer. . Ed

Numbers_Word_Problems/188541: The square of a number decreased by 5 is the same as 3 more than 7 times the number. Find the number. 1 solutions Answer 141367 by edjones(7569)   on 2009-03-26 22:56:28 (Show Source): You can put this solution on YOUR website! Let x be the number. x^2-5=7x+3 x^2-7x-8=0 (x-8)(x+1)=0 x=8 or x=-1 . Ed

Miscellaneous_Word_Problems/188208: 1. In 3 weeks a theater sold $9500 worth of tickets per week. For each of the next 2 weeks, the theater sold $7200 worth of tickets per week. What were the total ticket sales? In faction or decimal 2. Aline walked 3/4 mile to school. Dave walked .75 mile to school. Aline said she walked farther than Dave. Is she correct? Explain. 1 solutions Answer 141192 by edjones(7569)   on 2009-03-25 20:46:22 (Show Source): You can put this solution on YOUR website! 1. 9500*3=$28500.00 . 3/4=.75 They both walked the same distance. . Ed

Polynomials-and-rational-expressions/188180: 2/x+5 plus 6/x-5 1 solutions Answer 141190 by edjones(7569)   on 2009-03-25 20:32:24 (Show Source): You can put this solution on YOUR website! 2/(x+5) + 6/(x-5) =([2(x-5)]+[6(x+5)])/(x^2-25) =[(2x-10)+(6x+30)]/(x^2-25) =(8x+20)/(x^2-25) . Ed

Proportions/188230: An artist wants her painting to be in the shape of a golden rectangle. if the length of the painting is 36 inches, then what should be the width? 1 solutions Answer 141084 by edjones(7569)   on 2009-03-24 22:47:26 (Show Source): You can put this solution on YOUR website! proportions of the golden rectangle=(1+sqrt(5))/2)=l/w x/36=2/(1+sqrt(5)) x=72/(1+sqrt(5)) =22.249..." . Ed

Polynomials-and-rational-expressions/188232: please factor out polynomial. 2x^4+x^3+16x+8 thanks 1 solutions Answer 141083 by edjones(7569)   on 2009-03-24 22:36:08 (Show Source): You can put this solution on YOUR website! 2x^4+x^3+16x+8 =x^3(2x+1)+8(2x+1) =(x^3+8)(2x+1) =(x+2)(x^2-2x+4)(2x+1) . Ed

Polynomials-and-rational-expressions/188231: Factor: negative 3x squared minus 13x minus 48 1 solutions Answer 141082 by edjones(7569)   on 2009-03-24 22:24:24 (Show Source): You can put this solution on YOUR website! -3x^2-13x-48 Not factorable.

Graphs/187691: This question is from textbook algebra 1 kuya allan! i try to solve this but my answer is wrong please help me how to find the answer of this given harshhh! -3x+y=4 3x-y=-6 sorry kuya allan if i disturb you! THANKS AGAIN HIHIHIHI! 1 solutions Answer 140727 by edjones(7569)   on 2009-03-22 01:35:37 (Show Source): You can put this solution on YOUR website! -3x+y=4 3x-y=-6 . y=3x+4 3x-(3x+4)=-6 substitute 3x+4 for y in the 2nd equation. 3x-3x-4=-6 0=-2 the answer is undefined. . Ed

Square-cubic-other-roots/187692: Simplify each of the following: 1. sqrt(40) 2. 2sqrt(125) I've tried a few things, but just can't seem to work it out, even though I know it is a simple question. 1 solutions Answer 140726 by edjones(7569)   on 2009-03-22 01:30:23 (Show Source): You can put this solution on YOUR website! 1. sqrt(40) =sqrt(10*4) =2sqrt(10) . 2. 2sqrt(125) =2sqrt(5^2*5) =10sqrt(5) . Ed

Polynomials-and-rational-expressions/187441: (10x^3+10x^2)/(x^7-40x^5) I need to simplify this to its fullest how can I do that? 1 solutions Answer 140725 by edjones(7569)   on 2009-03-22 01:23:28 (Show Source): You can put this solution on YOUR website! (10x^3+10x^2)/(x^7-40x^5) [10x^2(x+1)]/[x^5(x^2-40)] [10(x+1)]/[x^3(x^2-40)] . Ed

Polynomials-and-rational-expressions/187561: 1 solutions Answer 140724 by edjones(7569)   on 2009-03-22 01:13:18 (Show Source): You can put this solution on YOUR website! Long division:5x^2+15x+40+(121/x-3) . Ed

Functions/186538: find the domain of: f(t)=log(t-5) 1 solutions Answer 139780 by edjones(7569)   on 2009-03-13 00:58:17 (Show Source): You can put this solution on YOUR website! f(t)=log(t-5) t(5, infinity) . Ed

Expressions-with-variables/186127: This question is from textbook Algebra 1 The sum of a two-digit number is 13. If the digits are reversed, the new number is 9 more than the original number. Find the original number. 1 solutions Answer 139575 by edjones(7569)   on 2009-03-11 01:19:21 (Show Source): You can put this solution on YOUR website! Let u=units digit & t=tens digit t+u=13 u=13-t . numb+ 9=new numb 10t+u+9=10u+t 10t+13-t+9=10(13-t)+t Substitute 13-t for u. 9t+22=130-10t+t 9t+22=130-9t 18t=108 t=6 u=7 . Ed

Exponential-and-logarithmic-functions/186124: log3 81= 1 solutions Answer 139573 by edjones(7569)   on 2009-03-11 01:05:50 (Show Source): You can put this solution on YOUR website! log3 81= . 3^4=81 So log3 81=4 . Ed

Polynomials-and-rational-expressions/186129: The volume of a carpet that is rolled up can be estimated by the polynomial πR^2h - πr^2h a) factor the polynomial b) Use both the original and the factored forms to find the volume of a roll for which R =50cm, r =10cm, and h =4m. Use 3.14 for π. 1 solutions Answer 139572 by edjones(7569)   on 2009-03-11 01:00:16 (Show Source): You can put this solution on YOUR website! πR^2h - πr^2h=(3.14*50^2*4)-(3.14*10^2*4)=31400-1256=30144 . πR^2h - πr^2h =pi*h(R^2-r^2) =3.14*4(2500-100) =12.56*2400 =30144 . Ed

Triangles/186134: This question is from textbook A Survey of Mathematics with Application I don't even no where to start with this problem: A diagonal walk through a small rectangular garden 9 meters by 12 meters can be built at $10 per linear meter. How much will the walk cost? 1 solutions Answer 139571 by edjones(7569)   on 2009-03-11 00:47:46 (Show Source): You can put this solution on YOUR website! The diagonal is the hypotenuse of a right triangle with sides of 9m and 12m. a^2+b^2=c^2 81+144=225 sqrt(225)=15m length of the diagonal 15*10=$150. cost of the walk. . Ed

Equations/186141: I am trying to help my ten year old son and am so lost. I am able to figure out for instance, n + 7 = 19. Then they rearranged the problem and asked him to solve 57 - w = 20. Not a clue. Thanks for your help. This is a teacher handwritten worksheet, so I do not have an ISBN. I do know that his school system uses the Everyday Math series. 1 solutions Answer 139569 by edjones(7569)   on 2009-03-11 00:39:51 (Show Source): You can put this solution on YOUR website! 57 - w = 20 -w=-37 Subtract 57 from each side of the equation. w=37 multiply each side by -1. . Ed

Miscellaneous_Word_Problems/186143: Joe can eat an Uranian sandwich in 25 minutes. Working together, Joe and Mark can eat the sandwich in 50/7 minutes. How many minutes would it take Mark to eat the sandwich by himself? 1 solutions Answer 139567 by edjones(7569)   on 2009-03-11 00:31:08 (Show Source): You can put this solution on YOUR website! Let x=minutes it takes for Mark to eat a sandwich. In 1 minute joe can eat 1/25 of a sandwich. In 1 minute together they can eat 7/50 of a sandwich. In 1 minute Mark can eat 1/x of a sandwich. . 1/25 + 1/x = 7/50 2x+50=7x Multiply each side by 50x to eliminate fractions. -5x=-50 x=10 min . Ed

Polynomials-and-rational-expressions/186138: please help me and show work. rq+2r+2qs+4s 1 solutions Answer 139564 by edjones(7569)   on 2009-03-11 00:18:58 (Show Source): You can put this solution on YOUR website! rq+2r+2qs+4s r(q+2)+2s(q+2) (r+2s)(q+2) . Ed