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edjones answered: 7568 problems
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expressions/432562: write without negative exponents 6 / 5z^-6 1 solutions Answer 299951 by edjones(7569)   on 2011-04-07 14:49:55 (Show Source): You can put this solution on YOUR website! 6 / 5z^-6 =6z^6/5

Numbers_Word_Problems/432579: one number is two times another. If the sum of their reciprocals is 1/2, find the two numbers. 1 solutions Answer 299950 by edjones(7569)   on 2011-04-07 14:47:12 (Show Source): You can put this solution on YOUR website! x=2y 1/x + 1/y = 1/2 2y+2x=xy multiply each side by 2xy 2y+4y=2y^2 substitute 2y for x -2y^2+6y=0 -2y(y-3)=0 y=3, x=6 . Ed

Polynomials-and-rational-expressions/432583: Express with a rational denominator -1+ the square root of -3 --------------------------- 1+ the square root of 3 (note: the dashes mean divided by.) 1 solutions Answer 299946 by edjones(7569)   on 2011-04-07 14:35:59 (Show Source): You can put this solution on YOUR website! (-1+sqrt(3))/(1+sqrt(3)) (-1+sqrt(3))/(sqrt(3)+1) * (-1+sqrt(3))/(sqrt(3)-1) =4-2sqrt(3)/2 =2-sqrt(3) . Ed

Miscellaneous_Word_Problems/432587: The product of two more than a number and three times the reciprocal of the number is 15/4. Find the number 1 solutions Answer 299942 by edjones(7569)   on 2011-04-07 14:19:21 (Show Source): You can put this solution on YOUR website! Let the number be x. (x+2)(3/x)=15/4 12(x+2)=15x Multiply each side by 4x to eliminate fractions. 12x+24=15x -3x=-24 x=8 . Ed

Probability-and-statistics/432592: A local fast-food restaurant has determined that 10% of drive-thru orders are filled incorrectly. Suppose 5 orders are randomly selected. what is the probability that more than one of the orders is filled incorrectly? 1 solutions Answer 299940 by edjones(7569)   on 2011-04-07 14:08:47 (Show Source): You can put this solution on YOUR website! p=.9, q=.1 p^5+5p^4q=.91854 probability one or none filled incorrectly. 1-.91854=.08146 the probability that more than one of the orders is filled incorrectly. . Ed

Expressions-with-variables/432598: (-5)(m)(m)(m)(n) 1 solutions Answer 299939 by edjones(7569)   on 2011-04-07 14:02:33 (Show Source): You can put this solution on YOUR website! -5m^3n

Miscellaneous_Word_Problems/432589: Suppose that P is proportional to Q. If p=40 when Q=9, find P when Q=24 1 solutions Answer 299934 by edjones(7569)   on 2011-04-07 13:49:34 (Show Source): You can put this solution on YOUR website! p/24=40/9 p=106.67 . Ed

Travel_Word_Problems/432517: From a point on a straight road, two cars are driven in opposite directions, one at 40 miles per hour and the other at 54 miles per hour. In how many hours will they be 282 miles apart? 1 solutions Answer 299877 by edjones(7569)   on 2011-04-07 10:54:51 (Show Source): You can put this solution on YOUR website! 54+40=94 miles apart in 1 hr. 282/94=3 hrs . Ed

Probability-and-statistics/432509: A person can have red hair. A person can have blue eyes. Are these events mutually exclusive? why or why not? 1 solutions Answer 299874 by edjones(7569)   on 2011-04-07 10:49:42 (Show Source): You can put this solution on YOUR website! No. A person with red hair can have blue eyes.

Probability-and-statistics/432512: Of ten dresses on a rack, three have a 1-inch hem, six have a 2-inch hem, and one has a 3-inch hem. Whats the expected hem of a dress randomly selected from this set? 1 solutions Answer 299868 by edjones(7569)   on 2011-04-07 10:43:35 (Show Source): You can put this solution on YOUR website! 3*1=3 6*2=12 1*3=3 . 3+12+3=18 18/10=1.8" the expected hem of a dress. . Ed

Probability-and-statistics/432506: Need some help with this problem, thank you for your time and consideration 23. Suppose that P (A) = x. The probability of the complementary event B is 0.7. What is the value of x? 1 solutions Answer 299861 by edjones(7569)   on 2011-04-07 10:31:23 (Show Source): You can put this solution on YOUR website! x=1-.7=.3

Probability-and-statistics/432497: Need some help with this problem... Thank you for your time and consideration 1. If a single letter is drawn from the set{m,a,t,h} what is the probability that the letter drawn is a member of the set {m, a, t, h, e, i, c, s}? 1 solutions Answer 299858 by edjones(7569)   on 2011-04-07 10:26:50 (Show Source): You can put this solution on YOUR website! The probability is 1 since all 4 letters are members of the second set.

Proportions/430146: 3k/5=k+6 what is the value of k 1 solutions Answer 298722 by edjones(7569)   on 2011-04-02 03:08:26 (Show Source): You can put this solution on YOUR website! 3k/5=k+6 3k=5k+30 Multiply each side by 5. -2k=30 k=-15 . Ed

Polynomials-and-rational-expressions/429826: Please help me solve: "Find a third degree polynomial equation with rational coefficients that has the given numbers as roots: -1, i+1 " I have the problem set up as: (x+1){x-(i+1)}{x-(i-1)} but I can't seem to solve it correctly. Please help! 1 solutions Answer 298541 by edjones(7569)   on 2011-04-01 02:25:44 (Show Source): You can put this solution on YOUR website! (x+1)(x-(i+1))(x-(i+1)) =-2x^2*-3x-1 . Ed

Radicals/429748: 5 radical 7 + 3 radical 28 I tried 5 radical 7 + 3 radical 28 5 radical 7 + 3 radical 14 radical 2 5 radical 7 + 3 radical 7 radical 2 radical 2 It's wrong! I really need help! 1 solutions Answer 298474 by edjones(7569)   on 2011-03-31 20:02:55 (Show Source): You can put this solution on YOUR website! 5sqrt(7)+3sqrt(28) =5sqrt(7)+3sqrt(7*4) =5sqrt(7)+6sqrt(7) =11sqrt(7) . Ed

Linear_Equations_And_Systems_Word_Problems/429763: The sum of the digits of certain two digit number is 7. Reversing its digits increases the number by 9. What is the number? And what is its linear equation? 1 solutions Answer 298471 by edjones(7569)   on 2011-03-31 19:56:06 (Show Source): You can put this solution on YOUR website! Let t=the tens digit and u=the units digit. 10t+u is the number. 10t+u=10u+t-9 9t-9u=-9 . t-u=-1 divide each side by 9 t+u=7 -------add 2t=6 . t=3 u=4 . Ed

Probability-and-statistics/429764: Two questions are on a test. There are 4 multiple choice answers for each question, but only one is right for each question. What is the probability you will get both questions correct. 1. A,B,C,D (Only one can be right) 2. A,B,C,D (Only one can be right) Probability of getting both questions correct? 1 solutions Answer 298464 by edjones(7569)   on 2011-03-31 19:41:40 (Show Source): You can put this solution on YOUR website! 1/4 * 1/4 = 1/16

Polynomials-and-rational-expressions/429392: please help me answer this question 1 solutions Answer 298289 by edjones(7569)   on 2011-03-31 01:31:57 (Show Source): You can put this solution on YOUR website! x^2-2x+1-8(x-1)-20=0 x^2-2x+1-8x+8-20=0 x^2-10x-11=0 (x-11)(x+1)=0 x=11, x=-1 . Ed

test/429402: solve system of equations by graphing. Show work. x+y=4 y-x=4 1 solutions Answer 298288 by edjones(7569)   on 2011-03-31 01:27:49 (Show Source): You can put this solution on YOUR website! x+y=4 y-x=4 -x+y=4 . x+y=4 -x+y=4 --------add 2y=8 . y=4 x=0 . Ed

Polynomials-and-rational-expressions/429410: Help please: I'm suppose to determine the polynomial equation that produced the given roots: These are of few of the problems: x = -2,7 x = 4,9 Then the other section states solve each equation: and this is one question: 7r2 = 70r-175 1 solutions Answer 298287 by edjones(7569)   on 2011-03-31 01:23:36 (Show Source): You can put this solution on YOUR website! x=-2, x=7 x+2=0, x-7=0 (x+2)(x-7)=0 x^2-5x-14=0 . Ed

Rectangles/429422: The length of a rectangle is 4cm, longer than its width. If the perimeter of the rectangle is 32cm , find its area. 1 solutions Answer 298286 by edjones(7569)   on 2011-03-31 01:20:25 (Show Source): You can put this solution on YOUR website! L=w+4 2(L+w)=p 2(w+4+w)=32 Substitute w+4 for L. 2(2w+4)=32 4w+8=32 4w=24 w=6 L=10 . Lw=A 10*6=60 cm^2 . Ed

Probability-and-statistics/429423: Two cards are are drawn from a standard deck of 52 cards. once a card is drawn, it is not replaced. Find the probability that you draw a queen followed by a jack as your first two cards. 1 solutions Answer 298285 by edjones(7569)   on 2011-03-31 01:14:54 (Show Source): You can put this solution on YOUR website! 4/52 * 4/51 = 4/663 . Ed

Probability-and-statistics/429454: A costume store sells 20 costumes, you and 3 friends go to the store separately. What is the probability that at least 2 of you pick the same costume ? 1 solutions Answer 298284 by edjones(7569)   on 2011-03-31 01:07:29 (Show Source): You can put this solution on YOUR website! 20/20 * 19/20 * 18/20 * 17/20 = .72675 Probability noone picks the same costume. 1-.72675=.27325 probability that at least 2 of you pick the same costume. . Ed

Square-cubic-other-roots/429464: 2.)Why do we have to check the solutions when we solve radical equations? 4.) √5x-4 = 6 8.) √y+10 = y-2 20.) √5x^2-3x = 2x 2.) The discriminant in the quadratic formula is the expression___________? 4.) If the discriminant in the quadratic formula is a perfect square, then the quadratic equation will have ______________solution(s)? Solve the Quadratic Formula. 6.) x^2 - 3x - 1 = 0 8.) 4x^2 + x -1 = 0 This is all the questions that I have for the remainder of the semester. I really appreciate your help and I am glad you are available for students like me. I've been trying to do this own my own for 10 weeks but the problems just got too hard for me and I've not been making the grade. Please let me know if I can do anything for any of you tutors, I will. Thanks again. We really appreciate your brains! You are impressive! All of you! 1 solutions Answer 298281 by edjones(7569)   on 2011-03-31 00:57:12 (Show Source): You can put this solution on YOUR website! 2.) The discriminant in the quadratic formula is the expression b^2-4ac.

Probability-and-statistics/429465: How can you make a fair game (one with probability 1/2 of winning) from tossing an unfair coin? If a coin has probability p of heads (with p not necessarily 1/2), show that for two tosses the events HT and TH have the same probability. Therefore, toss the coin twice: If you get HT call the result a "win," if you get TH call the result a "lose," and if you get HH or TT ignore those tosses and toss it twice more, repeating the procedure until you get HT or TH. "Win" and "lose" are equally likely, so each has probability 1/2 of occurring first. Any help is great THXS 1 solutions Answer 298278 by edjones(7569)   on 2011-03-31 00:53:54 (Show Source): You can put this solution on YOUR website! This explains how to make a fair game from tossing an unfair coin. It is not asking you anything.

Expressions-with-variables/429468: Having trouble with this problem 1/a + 1/b = c solve for a 1 solutions Answer 298276 by edjones(7569)   on 2011-03-31 00:47:32 (Show Source): You can put this solution on YOUR website! 1/a + 1/b = c b+a=abc Multiply each side by ab. a-abc=-b a(1-bc)=-b a=-b/-(bc-1) a=b/(bc-1) . Ed

Equations/429013: 2x+4=5x+18 1 solutions Answer 298078 by edjones(7569)   on 2011-03-29 23:47:41 (Show Source): You can put this solution on YOUR website! 2x+4=5x+18 -3x=14 Add -5x-4 to each side. x=-14/3 divide each side by -3 . Ed

Permutations/429029: How many ways can an 8 person tennis team be chosen from 17 students? 1 solutions Answer 298076 by edjones(7569)   on 2011-03-29 23:41:34 (Show Source): You can put this solution on YOUR website! nCr: Combination of n things taken r at a time=n!/((n-r)!*r!) 17!/(9!*8!) =24,310 . Ed

Probability-and-statistics/427247: 1. A multiple choice test has 30 questions, and each has five possible answers, of which one is correct. If a student guesses on every question, find the probability of getting exactly 40% correct. I understand n=30 and p=0.20 but the 40% correct is confusing me. Please help. 2. What is the probability that 4 rolls of a fair die will show exactly three fours? 1 solutions Answer 297110 by edjones(7569)   on 2011-03-25 23:57:29 (Show Source): You can put this solution on YOUR website! 30*.4=12 questions p=.2, q=.8 30C12=86493225 combination of 30 things taken 12 at a time. 86493225*p^12*q^18=.0064 . Ed

Miscellaneous_Word_Problems/426941: Minimizing cost. A company uses the formula C(x) = 0.02x² - 3.4x + 150 to model the unit cost in dollars for producing x stabilizer bars. For what number of bars is the unit cost at its minimum? What is the unit cost at that level of production? 1 solutions Answer 296924 by edjones(7569)   on 2011-03-25 01:13:58 (Show Source): You can put this solution on YOUR website! C(x) = 0.02x² - 3.4x + 150 -b/2a is the minimum -(-3.4)/2(.02) =3.4/.04 =85 bars . .02*85^2-3.4*84+150 =144.5-289+150 =$5.50 unit cost . Ed .

logarithm/426951: How do I solve this Logarithmic function? The initial population of bacteria is 250. The number of bacteria doubles every 15 minutes. Predict the bacteria population after 3 hours. Please show steps! 1 solutions Answer 296923 by edjones(7569)   on 2011-03-25 00:43:54 (Show Source): You can put this solution on YOUR website! 3*60=180 180/15=12 doublings a[12]=a[1]r^(12-1) geometric sequence. r=2, a[1]=250 =250*2^11 =250*2048 =512,000 . Ed