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# Recent problems solved by 'rapaljer'

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 Numeric_Fractions/174557: 3/8 x +5/6=2/3 what value is x?1 solutions Answer 129565 by rapaljer(4667)   on 2008-12-29 21:10:12 (Show Source): You can put this solution on YOUR website!I am assuming that the x is NOT in a denominator. If this was NOT your intention, you'll have to resubmit the problem. The LCD for the denominators of 8, 6, and 3 will be 24, so multiply both sides by 24. R^2
 Linear_Equations_And_Systems_Word_Problems/174555: 500 students are enrolled in at least two of these three classes: Math, English, and History. 170 are enrolled in both Math and English, 150 are enrolled in both History and English, and 300 are enrolled in Math and History. How many of the 500 students are enrolled in all three? 1 solutions Answer 129564 by rapaljer(4667)   on 2008-12-29 21:01:53 (Show Source): You can put this solution on YOUR website!Let x = number of students enrolled in all three classes. Since students are enrolled in at least two classes, there are four categories of students summarized below. x= Students in all three classes 170 -x = students in math and English but not history 150 - x = students in English and history but not math 300 - x = students in history and math but not English The sum of these students must equal 500. x + 170-x + 150-x + 300-x = 500 620-2x = 500 -2x = -120 x=60 R^2
 Quadratic_Equations/174558: I attempted to help my friend with her homework but I got stumped by this problem as well. She told me the problem was a quadratic equation but it's not in standard quadratic form. Anyways, the problem is: 47816=x^2=450x1 solutions Answer 129563 by rapaljer(4667)   on 2008-12-29 20:51:31 (Show Source): You can put this solution on YOUR website!You must have mistyped the equation. You have two equal signs. By the way, if the equation is NOT in standard form, your first step is to get it into standard form by setting the equation equal to zero. Try again and repost it, or send me an Email. By the way, what method were you supposed to use? With these big numbers, it's going to be hard to factor. The quadratic formula will have some big numbers but it's okay. Have you done the completing the square method? R^2
 Inequalities/174544: p+(-8)<(and equal to) -12 This problem is from the glencoe pre-algebra practice workbook. Isbn: 0-07-827789-21 solutions Answer 129555 by rapaljer(4667)   on 2008-12-29 15:40:42 (Show Source): You can put this solution on YOUR website!Just add +8 to each side of the inequality: R^2
 Average/174543: If Steven can mix 20 drinks in 5 minutes, Sue can mix 20 drinks in 10 minutes, and Jack can mix 20 drinks in 15 minutes, how much time will it take all 3 of them working togeter to mix 20 drinks?1 solutions Answer 129554 by rapaljer(4667)   on 2008-12-29 15:36:44 (Show Source): You can put this solution on YOUR website!If Steven can mix 20 drinks in 5 minutes, then in 1 minute he can mix 4 drinks. If Sue can mix 20 drinks in 10 minutes, then in 1 minute she can mix 2 drinks. If Jack can mix 20 drinks in 15 minutes, then in 1 minute he can mix 20/15 =4/3 drinks. Let x = time it will take all 3 mixing drinks together to mix 20 drinks. Then in 1 minute, all will be able to mix 20/x drinks. Now, number of drinks of Steven in 1 minute + no drinks by Sue in 1 minute + no drinks by Jack in 1 minute = Number of drinks by all in 1 minute. Multiply both sides of the equation by the LCD which is 3x: minutes (approximately) R^2
 Rational-functions/172338: This question is from textbook advanced mathematical concepts list the possible rational roots of each equation. the determine the rational roots x to the third power + 2x to the second power - 6=o.1 solutions Answer 129553 by rapaljer(4667)   on 2008-12-29 15:13:31 (Show Source): You can put this solution on YOUR website!Since the leading coefficient is 1, the possible rational roots must be factors of the constant term, which is -6. Therefore, the possible rational roots are +1,-1, +2, -2, +3, -3, 6, and -6. R^2
 Rational-functions/172340: This question is from textbook advanced mathematical concepts list the possible rational roots of each equation. the determine the rational roots x to the third power + 2x to the second power - 6=o.1 solutions Answer 129552 by rapaljer(4667)   on 2008-12-29 15:11:41 (Show Source): You can put this solution on YOUR website!Since the leading coefficient is 1, the possible rational roots must be factors of the constant term, which is -6. Therefore, the possible rational roots are +1,-1, +2, -2, +3, -3, 6, and -6. R^2
 Polynomials-and-rational-expressions/172280: factor x to the 4th - 11 solutions Answer 129551 by rapaljer(4667)   on 2008-12-29 15:08:17 (Show Source): You can put this solution on YOUR website!(x^4 -1) (x^2-1)(x^2+1) (x-1)(x+1)(x^2+1) R^2
 Functions/172375: Determine the domain of the function p(x)=3x^2-5x-2/x^2-41 solutions Answer 129550 by rapaljer(4667)   on 2008-12-29 15:04:09 (Show Source): You can put this solution on YOUR website! Domain requires that denominators must NOT equal zero! In this case, x canNOT equal 2 or -2. Domain therefore is all values of x except 2 and -2. In interval notation: (-inf, -2) U (-2,2) U (2, inf). R^2
 Square-cubic-other-roots/172252: x²- 180= 0 1 solutions Answer 129549 by rapaljer(4667)   on 2008-12-29 14:59:29 (Show Source): You can put this solution on YOUR website!x^2=180 or R^2
 Linear-systems/172345: 1 times a number plus -5 that will give me an answer of -31 solutions Answer 129547 by rapaljer(4667)   on 2008-12-29 14:53:57 (Show Source): You can put this solution on YOUR website!Let x = the number 1x -5 = -3 x-5+5 = -3+5 x= 2 R^2
 Travel_Word_Problems/174514: This question is from textbook 1 solutions Answer 129543 by rapaljer(4667)   on 2008-12-29 13:47:58 (Show Source): You can put this solution on YOUR website!Please state the problem??? R^2
 Travel_Word_Problems/174532: Two cars driving on opposite sides of the freeway are 20 miles apart and moving directly towards each other. one car is moving at 55 miles per hour, while the other ismoving at 70 miles per hour. How long will it take the two cars to pass each other? 1 solutions Answer 129542 by rapaljer(4667)   on 2008-12-29 13:46:19 (Show Source): You can put this solution on YOUR website!Since the cars are moving towards each other, you can ADD their speeds together. The distance between them is closing at a rate of 55 + 70 miles per hour, or a total of 125 mph. The TIME it takes to close the distance of 20 miles is given by the formula , so hours. That probably doesn't mean very much to you, so convert this to minutes by multiplying by 60. That would be t= 0.16 hours * 60 = 9.6 minutes. Keep that in mind the next time you decide to drink and drive!!! R^2
 Square-cubic-other-roots/174534: i am doing my algebra 2 (10th grade) class on plato, an online schooling program. which i need some major help with. i cant find it anywhere, so i figured id give this a go. please help me solve this equation. thanks1 solutions Answer 129540 by rapaljer(4667)   on 2008-12-29 13:39:41 (Show Source): You can put this solution on YOUR website!Is this your problem? ??? If so, multiply the radicands (inside the square roots!) together to get Sort out the perfect squares by forming two square roots: Simplify the square root that is a perfect square: If you need resources and explanations that PLATO does NOT provide, then you need to see my website!! Click on my tutor name, "rapaljer" anywhere in algebra.com, and then take my first main link on my homepage which is "Basic, Intermediate, and College Algebra: One Step at a Time." Go to Basic Algebra, Chapter 5, and you will find the ENTIRE chapter on Square Roots, complete with explanations, examples, exercises, and answers in a Discovery Method format, a LOT easier to understand than PLATO, and UNLIKE PLATO, IT's ALL FREE!!!! Send me an Email if you need more help!!! R^2
 Radicals/174533: SQRT(x2) = x A) all real numbers B) 0 C) {0,1} D) x<=0 E) none of the above F) x>=01 solutions Answer 129538 by rapaljer(4667)   on 2008-12-29 13:29:39 (Show Source): You can put this solution on YOUR website!The correct answer is F, since by Principle Value Definition of square root, it is required that x be greater than or equal to zero. R^2
 Polynomials-and-rational-expressions/174540: Rationalize the denominator of the expression. Assume that all variables are postive when they appear. 1. 4/√x+h-√x The answer I have is A. 4(√x+h-√x/h B. 4(√x+h+√x/h or C. 4√x+h+√x/h or D. 4√h/h I choosen D is that correct? 2. √5/√2+3 I have chosen √10+3√5/-7 for my answer is that correct? 3. Simplify the expression : √32x^2y/49 I have choosen 4√2x^2y/7 is that correct or is it 4x√2y/7? I am stuck. Can you help me? Thank you1 solutions Answer 129537 by rapaljer(4667)   on 2008-12-29 13:25:21 (Show Source): You can put this solution on YOUR website!1. Was the problem stated: ??? If so, the answer is . I think that would be B, but you forgot to close the parentheses in the numerator. 2. Looks correct! 3. = = = R^2
 Polynomials-and-rational-expressions/174538: Find the REAL Somution of the equation 2(x+1)^2+14(x+1)+20=0 The answers I have are A. (-5/2,-5) B. (-2,-6) C. (3/2,4) or D. (-5/2,-6) I keep getting -3,-6 what is the correct answer? I am stuck. Can you help me? Thank you1 solutions Answer 129536 by rapaljer(4667)   on 2008-12-29 13:17:13 (Show Source): You can put this solution on YOUR website!2(x+1)^2+14(x+1)+20=0 Factor out the common factor of 2, or, better yet, divide both sides by 2: (x+1)^2+7(x+1)+10=0 This factors into ((x+1) +5)*((x+1) + 2)=0 (x+6)(x+3)=0 x=-6 or x= -3 I don't see the correct answer here. Did you copy the multiple choices correctly??? Also, there are other methods to solve this, in case I confused you with this solution. ALTERNATE SOLUTION (for anyone who did not understand the above solution!) This trinomial factors into the product of two binomials: x= -6 or x = -3 Different method, same solution!! I KNOW this is correct!! The given answers are WRONG!! R^2
 Miscellaneous_Word_Problems/174536: During an intrumural basketball game, Team A scored 12 fewer points than Team B. Together, both teams scored a total of 144 points. How many points did Team A score during the game? The answer I got is A. 66 points. B. 67 points C. 72 points or D. 78 points. I chosen 72 points is that right? Can you help me? Thank you1 solutions Answer 129535 by rapaljer(4667)   on 2008-12-29 13:10:45 (Show Source): You can put this solution on YOUR website!Let x= points scored by team B, x-12 = points scored by team A. x+ x-12 = 144 2x=144 + 12 2x= 156 x=78 points scored by team B x-12 = 66 points scored by team A The correct answer is A. You can check this by adding 66 + 78 = 144 R^2
 absolute-value/174537: I require assistance solving this absolute value equation: 12=-4|k|1 solutions Answer 129534 by rapaljer(4667)   on 2008-12-29 13:06:45 (Show Source): You can put this solution on YOUR website!Divide both sides by -4, and you get |k| = -3 There is no real solution, since the absolute value of a number cannot equal a negative. R^2
 Functions/174539: 1 solutions Answer 129533 by rapaljer(4667)   on 2008-12-29 13:04:22 (Show Source): You can put this solution on YOUR website!You have to state the problem. We don't have your book!! R^2
 Surface-area/174502: I want to know how many bricks and cement it would take to build the following brick wall: the bricks are 16 inches by 8 inches, and the wall would measure 6 ft high by 200 ft long...1 solutions Answer 129530 by rapaljer(4667)   on 2008-12-29 10:30:03 (Show Source): You can put this solution on YOUR website!The previously posted answer to this problem is WRONG!! You can't build a wall that BIG with 113 bricks!! I worked the problem in feet. The height of the wall is 6 feet. If the bricks are laid with lengthwise, the height of each brick would be 8 inches or of a foot. divided by bricks high If the length of the wall is 200 feet, and the length of each brick is 16 inches or feet, then the length of the wall is divided by bricks long. The number of bricks needed is 9 * 150 = 1350 bricks, not allowing for any wasted bricks. The previously posted answer is INCORRECT because of the most common error perimeters, areas, and volumes!! When a conversion was made from FEET to INCHES, it was noted that there are 12 INCHES in 1 FOOT! HOWEVER, in this problem you are dealing with AREA, so you must use SQUARE INCHES and SQUARE FEET!! This should have been 144 SQUARE INCHES in 1 SQUARE FOOT! In fact, if you multiply the WRONG ANSWER times 12, you get approximately the CORRECT ANSWER (except for the round off error that occurred!! So, that's my FINAL ANSWER: 1350 BRICKS!! R^2