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# Recent problems solved by 'fractalier'

 Money_Word_Problems/40179: Jill has \$3.50 in nickels and dimes. If she has 50 coins, how many of each type of coin does she have? 1 solutions Answer 25702 by fractalier(2141)   on 2006-06-01 12:54:18 (Show Source): You can put this solution on YOUR website! Let n be the number of nickels and d be the number of dimes. Their values are then 5n and 10d. The equations we write are 5n + 10d = 350 (thinking in cents now) n + d = 50 Let's multiply the bottom one by 5 and subtract it from the top one... 5n + 10d = 350 -(5n + 5d = 250) we get 5d = 100 d = 20 so then we get n = 30
 Functions/40190: Is this relation a function? {(0,5),(1,10),(2,15),(1,20)} 1 solutions Answer 25701 by fractalier(2141)   on 2006-06-01 12:51:31 (Show Source): You can put this solution on YOUR website! A relation. Notice that there are two different y-values for x = 1. Can't be a function because of that...
 Quadratic_Equations/40205: i need help with this equation n squared +n+1=0 1 solutions Answer 25700 by fractalier(2141)   on 2006-06-01 12:50:15 (Show Source): You can put this solution on YOUR website! n^2 + n + 1 = 0 is solved by the quadratic formula... n = (-1 ± sqrt(1 - 4)) / 2 n = (-1 ± i*sqrt(3)) / 2 that's the best we can do...
 expressions/40184: im lost on how to evalvaute. / 11 / + / -11 / But these / are straight lines 1 solutions Answer 25699 by fractalier(2141)   on 2006-06-01 12:45:21 (Show Source): You can put this solution on YOUR website! Yes, I know what you mean...these are absolute values... |11| + |-11| = 11 + 11 = 22 Absolute values are always positive (except for zero)...
 absolute-value/36619: What is the answer to "Simplify: 5/x+2 - 8/x+4" 1 solutions Answer 25698 by fractalier(2141)   on 2006-06-01 12:43:42 (Show Source): You can put this solution on YOUR website! We need to make the denominators the same in order to combine the fractions, so we get 5/x+2 - 8/x+4 = 5(x+4) / (x+2)(x+4) - 8(x+2) / (x+2)(x+4) = 5(x+4) - 8(x+2) / (x+2)(x+4) = (5x + 20 - 8x - 16) / (x+2)(x+4) = (-3x + 4) / (x+2)(x+4) and we're done...
 Mixture_Word_Problems/40193: Business and finance. A coffee merchant has coffee beans that sell for \$9 per pound and \$12 per pound. The two types are to be mixed to create 100 lb of a mixture that will sell for \$11.25 per pound. How much of each type of bean should be used in the mixture? Thank You 1 solutions Answer 25697 by fractalier(2141)   on 2006-06-01 12:40:54 (Show Source): You can put this solution on YOUR website! Posted this solution within the past two or three days...25 lbs at \$9 and 75 lbs at \$12...
 Proportions/40196: This question is from textbook i need a little help on proportions x over 5 = 3 over 4 1 solutions Answer 25696 by fractalier(2141)   on 2006-06-01 12:39:48 (Show Source): You can put this solution on YOUR website! Okay, we cross-multiply and solve for x...like this... From x/5 = 3/4, we get 4x = 15 x = 15/4
 real-numbers/40208: is this rational or irrational?? sqrt 71 1 solutions Answer 25695 by fractalier(2141)   on 2006-06-01 12:38:26 (Show Source): You can put this solution on YOUR website! Irrational. The square root of every non-perfect-square is irrational. It cannot be expressed as a fraction of two integers.
 absolute-value/40271: what is the smallest and biggest .8, 3, - 4, 9 isn't -4 the smallest #, and .8 the bigest 1 solutions Answer 25694 by fractalier(2141)   on 2006-06-01 12:36:58 (Show Source): You can put this solution on YOUR website! Well .8 is the smallest number (-4 has the least value, however). 9 is the largest number. This lesson is all about absolute value, that is, the distance a number is from zero on the number line.
 Permutations/16178: Six strangers arrive at a business seminar and each person shakes hands with every other person. How many handshakes are there? 1 solutions Answer 25693 by fractalier(2141)   on 2006-06-01 12:35:16 (Show Source): You can put this solution on YOUR website! Each man shakes hands with 5 other men, for a total of 30 handshakes. However, if man A shakes hands with man B, it is the same as B with A. Therefore we divide our total by two and get the answer... 15 handshakes Another way is 5+4+3+2+1 = 15...
 Equations/40307: 8x/x+1=4-8/x+1 1 solutions Answer 25689 by fractalier(2141)   on 2006-06-01 12:31:24 (Show Source): You can put this solution on YOUR website! Let us clear all the fractions by multiplying by x+1, so we get 8x/x+1 = 4 - 8/x+1 (x+1)[8x/x+1 = 4 - 8/x+1] 8x = 4(x + 1) - 8 8x = 4x + 4 - 8 8x = 4x - 4 4x = -4 x = -1 But look at the original problem... x can't be -1 !! Therefore, there is NO SOLUTION.
 Quadratic_Equations/40200: Find the center of the circle. x^2+y^2-4x-12y+30=0 1 solutions Answer 25674 by fractalier(2141)   on 2006-06-01 11:37:00 (Show Source): You can put this solution on YOUR website! We complete the square twice...once for x and once for y...we get x^2 + y^2 - 4x - 12y + 30 = 0 x^2 - 4x + y^2 - 12y + 30 = 0 x^2 - 4x + 4 + y^2 - 12y + 36 = -30 + 4 + 36 (x - 2)^2 + (y - 6)^2 = 10 center at (2, 6) radius is sqrt(10)
 Polynomials-and-rational-expressions/40218: Dr Wellbee advised his patients to drink 8 eight-ounce glasses of water everyday for every 50 pounds of weight. If Kelby weighs 200 pounds how many glasses of water should he drink in one week? Thanx 1 solutions Answer 25672 by fractalier(2141)   on 2006-06-01 11:34:48 (Show Source): You can put this solution on YOUR website! Similar to my last posting... she has to drink for a 200-lb person...thus 4 times 50 pounds...thus 4 times 8 glasses per day. She has to drink 32 glasses in one day or 32 x 7 = 224 glasses in one week.
 Polynomials-and-rational-expressions/40224: Dr Wellbee advised his patients to drink 8 eight-ounce glasses of water everyday for every 50 pounds of weight. Kelby drank 168 glasses of water in one week. How did Kelby probably weigh? Thanx 1 solutions Answer 25671 by fractalier(2141)   on 2006-06-01 11:33:02 (Show Source): You can put this solution on YOUR website! Well if she drank 168 glasses in one week, that averages out to 168/7 or 24 glasses per day. If she is supposed to drink 8 glasses per 50 pounds and she drank 24 glasses (3 times as much), she must weigh 3 times 50 or 150 pounds.
 Polynomials-and-rational-expressions/40226: If 15 pounds of fertillizer will cover 1500 square feet of lawn, how much fertilizer is needed to cover 2500 square feet? It would require ______ pounds to cover 2500 square feet. Thanx 1 solutions Answer 25670 by fractalier(2141)   on 2006-06-01 11:30:29 (Show Source): You can put this solution on YOUR website! Set up a proportion, cross-multiply and solve for x...here goes... 15 / 1500 = x / 2500 (you should be able to see the answer 25 already, but...) 1500x = 37500 x = 37500/1500 x = 25 pounds
 Quadratic_Equations/40304: I am having major problems solving by completing the square 2x^2-6x=5. I have no idea where to begin 1 solutions Answer 25668 by fractalier(2141)   on 2006-06-01 11:28:18 (Show Source): You can put this solution on YOUR website! The first step is to divide everything by 2...so we have 2x^2 - 6x = 5 x^2 - 3x = 5/2 Now continue with the standard procedure (except that this one involves yucky fractions)...lol... x^2 - 3x + 9/4 = 5/2 + 9/4 (half of 3 squared is 9/4) (x - 3/2)^2 = 10/4 + 9/4 (x - 3/2)^2 = 19/4 now take the square root of both sides x - 3/2 = ± sqrt(19/4) x - 3/2 = ± sqrt(19) / 2 x = (3 ± sqrt(19)) / 2
 Quadratic_Equations/40303: I am having problems completing the square x^2-8x=10. Below is the steps that I have taken: x^2-8x+16=10+16 x^2-8x =26 (x-4)^2=26 This is where I am completely lost. 1 solutions Answer 25667 by fractalier(2141)   on 2006-06-01 11:23:52 (Show Source): You can put this solution on YOUR website! From x^2 - 8x = 10, you are right if you have x^2 - 8x + 16 = 10 + 16 x^2 - 8x + 16 = 26 (x - 4)^2 = 26 Now take the square root of both sides and solve for x, giving you x - 4 = ± sqrt(26) x = 4 ± sqrt(26) and we're done...
 Money_Word_Problems/40217: This question is from textbook Beginning Algebra Business & Finace A coffee merchant has coffee beans that sell for \$9 per pound and \$12 per pound. The two types are to be mixed to create 100 lb. of a mixture that will sell for \$11.25 per pond. How much of each type of bean should be used in the mixture? 1 solutions Answer 25666 by fractalier(2141)   on 2006-06-01 11:20:57 (Show Source): You can put this solution on YOUR website! Posted this solution in the past two days...25 lbs at \$9...75 lbs at \$12...
 Expressions-with-variables/40230: Evaluate the expression when a = -5, b = 16, and c = 7. 7b + 10/a - √b 1 solutions Answer 25665 by fractalier(2141)   on 2006-06-01 11:18:59 (Show Source): You can put this solution on YOUR website! Plugging our values in to 7b + 10/a - sqrt(b) gives us 7(16) + 10/(-5) - sqrt(16) = 112 - 2 - 4 = 106
 Exponents/40235: ac-1 - a-1c (A times C to the negative one MINUS A to the negative one times C) 1 solutions Answer 25664 by fractalier(2141)   on 2006-06-01 11:16:17 (Show Source): You can put this solution on YOUR website! ac^(-1) - a^(-1)c = a/c - c/a = a^2/ac - c^2/ac = (a^2 - c^2) / ac
 Inequalities/40233: Rewrite the statement so the inequality symbol point the opposite direction. 5 £ 14 1 solutions Answer 25663 by fractalier(2141)   on 2006-06-01 11:13:35 (Show Source): You can put this solution on YOUR website! 5 < 14 becomes 14 > 5 and vice-versa
 Miscellaneous_Word_Problems/40257: A bacteria culture has an initial population of 10000. If its population declines to 3000 in 2 hours, what will the population be at the end of 4 hours? 1 solutions Answer 25662 by fractalier(2141)   on 2006-06-01 11:09:55 (Show Source): You can put this solution on YOUR website! Well if we assume exponential population decay (quite an assumption but I think that's what you need here)...our equation is P(t) = P(0)*e^rt Now plug in what we are given and solve for the rate, r...here goes... 3000 = 10000*e^(2r) e^(2r) = .3 ln e^2r = ln .3 2r = ln .3 r .5 ln .3 r = -.6 Now we plug that back into the original equation to find P(t)... P(t) = P(0)*e^rt P(t) = 10000*e^(-.6*4) P(t) = 10000*e(-2.4) P(t) = 907
 Numeric_Fractions/40265: [2+3) power 2 - 3 .5 +7 thank you sarah 1 solutions Answer 25661 by fractalier(2141)   on 2006-06-01 11:00:32 (Show Source): You can put this solution on YOUR website! Just posted this solution...
 Rational-functions/40229: simplify (-3s)(4p)+(-4s)(3p) Thank you 1 solutions Answer 25660 by fractalier(2141)   on 2006-06-01 10:58:54 (Show Source): You can put this solution on YOUR website! (-3s)(4p)+(-4s)(3p) = -12ps + (-12ps) = -24ps
 Mixture_Word_Problems/40300: The average number of red blood cells in 1mm(cube) of human blood is about 4500000. In order to perform a blood test, a lab tech dilute one part blood with 300 part salin solution. How many red bleed cells would you expect to find in 0.25mm(cube) of the solution? 1 solutions Answer 25659 by fractalier(2141)   on 2006-06-01 10:58:07 (Show Source): You can put this solution on YOUR website! Just posted this solution...
 Mixture_Word_Problems/40301: The average number of red blood cells in 1mm(cube) of human blood is about 4500000. In order to perform a blood test, a lab tech dilute one part blood with 300 part salin solution. How many red bleed cells would you expect to find in 0.25mm(cube) of the solution? 1 solutions Answer 25658 by fractalier(2141)   on 2006-06-01 10:57:32 (Show Source): You can put this solution on YOUR website! Well if 1 cubic mm of blood has 4,500,000 cells, then .25 cubic mm would have 1/4 of that or 1,125,000 cells. Now if that solution is diluted 1:300, you would expect 1/300 of the normal number of cells in the saline solution, thus... (1/300)(1,125,000) = 3750 cells
 absolute-value/40273: Which number lies farthest from the origin? -2,6,-1,0,3,5 1 solutions Answer 25657 by fractalier(2141)   on 2006-06-01 10:54:43 (Show Source): You can put this solution on YOUR website! The number with the greatest absolute value is farthest from the origin...here that number would be 6
 absolute-value/40275: Which number has the largest and smallest absolute value .9,0,-2,3,6 1 solutions Answer 25656 by fractalier(2141)   on 2006-06-01 10:53:47 (Show Source): You can put this solution on YOUR website! Just posted this solution...
 Numeric_Fractions/40260: I'm trying to type this out the best way. Straight Line 11 Straight Line + Straight Line - 11 Straight Line straight line looks like a straight line in between of the two different numbers like thanks sarah [ 11 ] + [ - 11 ] 1 solutions Answer 25655 by fractalier(2141)   on 2006-06-01 10:53:10 (Show Source): You can put this solution on YOUR website! Just posted this solution...22
 Average/40278: what is the smallest absoult value,and the biggest absolut value. -9,0,-2,3,6 1 solutions Answer 25654 by fractalier(2141)   on 2006-06-01 10:52:37 (Show Source): You can put this solution on YOUR website! Look at my last posting, but here... The smallest absolute value is 0. The largest absolute value is -9.
 logarithm/40276: Which number lies farthest from the origin? -9,0,-2,3,6 1 solutions Answer 25653 by fractalier(2141)   on 2006-06-01 10:51:23 (Show Source): You can put this solution on YOUR website! The number with the greatest absolute value is farthest from the origin...here that would be -9