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# Recent problems solved by 'scott8148'

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 Linear-equations/146237: -3(-x+4) = 3x-12 I tried distributing the first expression: 3x - 12 = 3x - 12 then add 12 to both sides: 3x = 3x then divide each side by 3: x = x is this possible? 1 solutions Answer 106776 by scott8148(6628)   on 2008-06-24 11:14:08 (Show Source): You can put this solution on YOUR website!not only possible, but guaranteed ... anything equals itself the point here is that x does not have a unique value ... any value will satisfy the equation
 Triangles/146181: This question is from textbook College Geometry Musser, Trimpe, and Maurer hi, i was wondering if you could help me on this partiular problem. i took a picture of it, to show what the problem is. please show work and explanation. this problem involves calculating the measure of each angle. here's the problem http://i32.tinypic.com/24zx06e.jpg thankyou. 1 solutions Answer 106740 by scott8148(6628)   on 2008-06-23 21:30:05 (Show Source): You can put this solution on YOUR website!c is the supplement of 60° __ c=120° g is vertical to a 60° angle __ g=60° f+40°+60°=180° __ f=80° d+110°+50°=180° __ d=30° e+60°+80°+30°=180° __ e=10° a=h __ a+h+40°=180° __ a=h=70° b=60°+70° __ b=130°
 Geometry_Word_Problems/145881: If you drew 11 rays in the interior of an angle how many angles have you formed?1 solutions Answer 106736 by scott8148(6628)   on 2008-06-23 20:54:55 (Show Source): You can put this solution on YOUR website!each ray makes two angles from one angle, so each additional ray means one additional angle 11 rays means 11 angles in addition to the original angle, so 12 angles
 Polynomials-and-rational-expressions/146164: Factor completely: 8x^2 – 200y^2 1 solutions Answer 106706 by scott8148(6628)   on 2008-06-23 18:09:26 (Show Source): You can put this solution on YOUR website!common factors first __ 8(x^2-25y^2) difference of squares __ 8(x+5y)(x-5y)
 Polynomials-and-rational-expressions/146166: How do you factor this completely? 7x^2 + 49x + 42 1 solutions Answer 106705 by scott8148(6628)   on 2008-06-23 18:07:43 (Show Source): You can put this solution on YOUR website!common factors first __ 7(x^2+7x+6) factors of 6 that "combine" to give 7 __ 7(x+6)(x+1)
 Polynomials-and-rational-expressions/146167: How do you completely factor this problem? 16a^3 - 36a^2y + 14ay^2 1 solutions Answer 106703 by scott8148(6628)   on 2008-06-23 18:02:14 (Show Source): You can put this solution on YOUR website!common factors first __ 2a(8a^2-18ay+7y^2) factors of 8 and 7 that "combine" to give -18 __ 2a(2a-y)(4a-7y)
 Polynomials-and-rational-expressions/146165: Can you help me factor this problem? 16a^3 - 36a^2y + 14ay^2 1 solutions Answer 106702 by scott8148(6628)   on 2008-06-23 18:01:44 (Show Source): You can put this solution on YOUR website!common factors first __ 2a(8a^2-18ay+7y^2) factors of 8 and 7 that "combine" to give -18 __ 2a(2a-y)(4a-7y)
 Linear-equations/145876: Write the equation of a line whose slope is 6 and whose y intercept is -3. 1 solutions Answer 106477 by scott8148(6628)   on 2008-06-20 15:03:49 (Show Source): You can put this solution on YOUR website!y=mx+b y=6x-3
 Polynomials-and-rational-expressions/145888: Factor completely: x^10 y^3 – 4x^9 y^2 – 21x^8 y 1 solutions Answer 106476 by scott8148(6628)   on 2008-06-20 14:55:04 (Show Source): You can put this solution on YOUR website!common factors first __ x^8*y(x^2*y^2-4xy-21) x^8*y(xy-7)(xy+3)
 Polynomials-and-rational-expressions/145892: Factor completely: x^2 + 9x + 8 1 solutions Answer 106475 by scott8148(6628)   on 2008-06-20 14:47:18 (Show Source): You can put this solution on YOUR website!(x+8)(x+1)
 Polynomials-and-rational-expressions/145893: Factor completely: 8x^2 – 200y^2 1 solutions Answer 106474 by scott8148(6628)   on 2008-06-20 14:46:26 (Show Source): You can put this solution on YOUR website!common factors first __ 8(x^2-25y^2) difference of squares __ 8(x+5y)(x-5y)
 Polynomials-and-rational-expressions/145894: Factor completely: 7x^2 + 58x + 16 1 solutions Answer 106473 by scott8148(6628)   on 2008-06-20 14:44:24 (Show Source): You can put this solution on YOUR website!(7x+2)(x+8)
 Polynomials-and-rational-expressions/145895: Factor completely: 7x^2 + 49x + 42 1 solutions Answer 106472 by scott8148(6628)   on 2008-06-20 14:42:45 (Show Source): You can put this solution on YOUR website!common factors first __ 7(x^2+7x+6) 7(x+6)(x+1)
 Linear_Algebra/145904: This question is from textbook Blitzer College Algebra z=2x+4y x>=0, y>=0 Linear programming problem, graphing a solution, and maximum. x+3y>=6 x+y>=3 x+y<=9 I come up with serveral vertices. Even when using the example. I know how to put the vertices back into the equations, but I need to figure out how to limit or pick the correct vertices; (0,0), (0,2), (6,0), (0,3), (3,0), (5,4), (6,3), (0,9) My graphe looks like a octagon kind of including 0. I am missing something and trying desperately to understand this. Can someone show me how I conclude which vertices are correct? Heidi1 solutions Answer 106471 by scott8148(6628)   on 2008-06-20 14:39:59 (Show Source): You can put this solution on YOUR website!you are trying to maximize z test the vertices by substituting into z=2x+4y to find the maximum some points can be eliminated by inspection __ (0,0) is obviously not the maximum __ (6,3) must be greater than each of the first five points in the list __ the maximum appears to be one of the last three points in the list
 Functions/145902: find the equation of the line containing the given pair (-5,-3) (-2,-4). I came up with: y=1/3x-4/3 but the systems says that it is not correct. Please help! Thank you1 solutions Answer 106470 by scott8148(6628)   on 2008-06-20 14:25:05 (Show Source): You can put this solution on YOUR website!the slope (m) is -1/3 (not 1/3) substituting to find the y-intercept (b) __ -3=(-1/3)(-5)+b __ -3=(5/3)+b __ -14/3=b y=(-1/3)x-(14/3)
 Rate-of-work-word-problems/145847: Hi, I am having difficulty putting this problem into an equation even though I know the answer. Workman A and B complete a certain job if they work together for 6 days or if A alone works for 3 days and B alone works for 10 days. How long does it take each man to complete the job alone? The answer is A - 10 1/2 days and B - 14 days Thank you for your help.1 solutions Answer 106444 by scott8148(6628)   on 2008-06-19 22:13:25 (Show Source): You can put this solution on YOUR website!let x="A time alone" and y="B time alone" "Workman A and B complete a certain job if they work together for 6 days" __ 6/x+6/y=1 "A alone works for 3 days and B alone works for 10 days" __ 3/x+10/y=1 __ multiplying by 2 __ 6/x+20/y=2 subtracting equations __ 6/x+20/y-(6/x+6/y)=2-1 __ 14/y=1 __ 14=y substituting __ 6/x+6/14=1 __ subtracting 6/14 __ 6/x=8/14 __ multiplying by 14x __ 84=8x __ dividing by 8 __ 10.5=x
 logarithm/145834: Please help! This has me stumped. I think this is a logarithm problem. Find the integer k such that 270k is a perfect square.1 solutions Answer 106429 by scott8148(6628)   on 2008-06-19 19:04:30 (Show Source): You can put this solution on YOUR website!depending on how you look at the problem... if k is a digit, then 52^2=2704 if the perfect square is the product of 270 and k prime factors of 270 __ 3*3*3*5*2 __ for a perfect square, even quantities of all prime factors 3*3*3*5*2*(3*5*2) __ 270*30=8100=90^2
 Miscellaneous_Word_Problems/145741: Eight adults and two children need to cross a river, and they have one small boat available to help them. The boat can hold either one adult, or one or two children. Everyone in the group is able to row the boat. Show how you get them all across the river. How many one-way trips does it take for the eight adults and two children to cross the river?1 solutions Answer 106417 by scott8148(6628)   on 2008-06-19 18:19:59 (Show Source): You can put this solution on YOUR website!two children cross __ one rows back __ one adult crosses __ child rows back repeat cycle until all adults are across (7 more times) last trip is two children crossing to join 8 adults 4*8+1 or 33 crossings
 Quadratic_Equations/145804: This is a verbal question that has to do with Quadratic Equations. Suppose 5 bales of hay are weighed 2 at a time in all possible ways. The weights in pounds are 110, 112, 113, 114, 115, 116, 117, 118, 120, and 121. How much does each of the 5 bales weigh? I'd appreciate any help with this problem. Thanks.1 solutions Answer 106414 by scott8148(6628)   on 2008-06-19 18:07:44 (Show Source): You can put this solution on YOUR website!call the bales (in order of increasing weight) A, B, C, D, E the lowest and highest weights are the 2 lightest and 2 heaviest respectively __ A+B=110 __ D+E=121 the 2nd lowest is the lightest bale with the middle bale __ A+C=112 the 2nd highest is the heaviest bale with the middle bale __ C+E=120 every bale is weighed with each of the other 4 bales, so every bale is weighed 4 times __ this means that the sum of the weights is 4 times the sum of the weights of the individual bales A+B+C+D+E=(110+112+113+114+115+116+117+118+120+121)/4 __ A+B+C+D+E=289 substituting __ 110+C+121=289 __ C=58 substituting __ A+58=112 __ A=54 substituting __ 54+B=110 __ B=56 substituting __ 58+E=120 __ E=62 substituting __ D+62=121 __ D=59
 Miscellaneous_Word_Problems/145744: Maria lights two candles of equal length at the same time. One candle takes six hours to burn out and the other takes nine. How much time will pass until the slower-burning candle is exactly twice as long as the faster-burning one?1 solutions Answer 106410 by scott8148(6628)   on 2008-06-19 16:57:35 (Show Source): You can put this solution on YOUR website!let x=time __ 2[(6-x)/6]=(9-x)/9 __ multiplying by 9 __ 3(6-x)=9-x __ 18-3x=9-x adding 3x-9 __ 9=2x __ 4.5=x
 Graphs/145528: If log a=.250 then what is log a^2?1 solutions Answer 106179 by scott8148(6628)   on 2008-06-16 20:54:38 (Show Source): You can put this solution on YOUR website!using rules of logs (and exponents) __ log(a^2)=2log(a) __ so log(a^2)=.5
 Exponential-and-logarithmic-functions/145459: log3 fifth root of 91 solutions Answer 106177 by scott8148(6628)   on 2008-06-16 20:52:24 (Show Source): You can put this solution on YOUR website!log3(9^(1/5)) __ log3[(3^2)^(1/5)] __ log3(3^(2/5))=2/5
 Expressions-with-variables/145337: Could someone please help me with a few problems on the Elimination Method? 1) 5x - y = 12 3x + y = 4 2) 2x - y = -6 2x - 2y = -4 I have the directions on how to work these problems, but I'm having a hard time understanding how to write them down on the paper.If you don't mind,would you please show me how they would look when you write them.That would help me understand it better,so when I take a test over this, I will know how it is suppose to look.1 solutions Answer 106013 by scott8148(6628)   on 2008-06-14 21:47:08 (Show Source): You can put this solution on YOUR website!to eliminate one of the variables, just arrange for the number value of the coefficients of the variable to be equal __ then add or subtract the equations as needed 1) the number value (absolute value) of the y-coefficients is the same (1) __ adding the two equations ELIMINATES the y giving 5x+3x=12+4 __ 8x=16 __ x=2 __ substituting __ 3(2)+y=4 __ 6+y=4 __ y=-2 2) the value of the x-coefficients is the same (2) __ subtracting the 2nd equation from the 1st gives -y-(-2y)=-6-(-4) __ y=-2 __ substituting __ 2x-(-2)=-6 __ 2x=-8 __ x=-4 you can "arrange" for the coefficients to be equal by multiplying one or both of the equations by the appropriate quantities
 Circles/145328: A circle with radius of 1 has a polygon with "n" sides inscribed in it. What is the limit of the area of the polygon? a. pi b. 2pi c. 4pi^2 d. none of the above I chose a. I was thinking that the area of they polygon cannot exceed the area of the circle which is pir^2 or in this case pi-- is this right?1 solutions Answer 106009 by scott8148(6628)   on 2008-06-14 21:30:57 (Show Source): You can put this solution on YOUR website!yes __ good work
 Proofs/145213: This question is from textbook I can't figure this. Can you help me. 7. (2 pts) Two balls are to be selected without replacement from a bag containing one red, one blue, one green, one yellow, and one black ball. How many points are there in the sample space? 5*4 = 20 ?? 1 solutions Answer 105884 by scott8148(6628)   on 2008-06-13 14:41:29 (Show Source): You can put this solution on YOUR website!close... whether you select red-blue or blue-red, the result is the same so half of 20 is the answer
 Miscellaneous_Word_Problems/145158: We're studying Logarithms in school and I understand it but have problems with word problems. Don't know how to even begin to set up an equation in form of a logarithm (possibly) to solve this word problem. Any help would be very appreciated. Thanks. A computer is infected with the Sasser virus. Assume that it infects 20 other computers within 5 minutes; and that these PCs and servers each infect 20 more machines within another five minutes, etc. How long until 100 million computers are infected?1 solutions Answer 105838 by scott8148(6628)   on 2008-06-12 22:33:53 (Show Source): You can put this solution on YOUR website!let t="time in minutes" __ 10^8=1[20^(t/5)] __ taking log __ log(10^8)=(t/5)log(20) dividing by log(20) __ 8/log(20)=t/5 __ multiplying by 5 __ 40/log(20)=t
 Matrices-and-determiminant/145151: Could someone please tell me if I'm right on these two Cramer rule problems? 1) 2x + 5y = 3 x + 4y = 2 I got(2/3,1/3) 2)x + 2y = 4 3x - 2y = -12 I got(-8,6) Thank you in advance for helping me. Sincerely, Elle J1 solutions Answer 105837 by scott8148(6628)   on 2008-06-12 22:27:07 (Show Source): You can put this solution on YOUR website!1st one yes, 2nd one no 2nd should be (-2,3)
 Quadratic-relations-and-conic-sections/144921: The graph of the equation below is an ellipse. What is the y-coordinate of the center of that ellipse? (x+3)^2/5^2+(y+9)^2/8^2=1 i had gotten 9 but it was wrong1 solutions Answer 105636 by scott8148(6628)   on 2008-06-11 09:51:00 (Show Source): You can put this solution on YOUR website!the number is right but the sign is wrong __ -9 is the y-coordinate a general equation is __ where (h,k) is the center
 Money_Word_Problems/144949: I am having a problem with an interest problem mainly because it has 3 unknowns. I can't seem to get the equations right. Can you help me? A man divides \$10000 among 3 investments, 3%, 4% and 6% per annum respectively. His annual income from the first two investments is \$80 less than his income from the third investment and his total income is \$460 per year. Find the amount invested at each rate. The answer is: 3% \$3000; 4% \$2500; 6% \$4500 Thank you for your time.1 solutions Answer 105635 by scott8148(6628)   on 2008-06-11 09:44:15 (Show Source): You can put this solution on YOUR website!let x="amount @ 3%", y="amount @ 4%", and z="amount @ 6%" "A man divides \$10000 among 3 investments" __ x+y+z=10000 "His annual income from the first two investments is \$80 less than his income from the third investment" __ (3%)x+(4%)y=(6%)z-80 "his total income is \$460 per year" __ (3%)x+(4%)y+(6%)z=460 substituting __ [(6%)z-80]+(6%)z=460 __ adding 80 __ (12%)z=540 __ dividing by 12% __ z=4500 substituting __ x+y+(4500)=10000 __ subtracting 4500 __ x+y=5500 __ subtracting x __ y=5500-x substituting __ (3%)x+(4%)y=(6%)(4500)-80 __ (3%)x+(4%)y=190 __ dividing by 4% __ .75x+y=4750 substituting __ .75x+(5500-x)=4750 __ subrtacting 5500 __ -.25x=-750 __ dividing by -.25 __ x=3000 substituting __ (3000)+y=5500 __ subtracting 3000 __ y=2500
 Quadratic_Equations/144780: If x = 3 and x = -5, then form a quadratic equation. 1 solutions Answer 105527 by scott8148(6628)   on 2008-06-10 13:46:57 (Show Source): You can put this solution on YOUR website!if n is a root (solution), then x-n is a factor (x-3)(x+5)=0 __ FOILing __ x^2+2x-15=0
 Percentage-and-ratio-word-problems/144787: In a barn every two horses share a trough, every three cows share a trugh and every eight pigs share a trough. The farmer has the same nuber of each animal. There is a total of sixty nine troughs. How many animals does the farmer have in total?1 solutions Answer 105522 by scott8148(6628)   on 2008-06-10 13:40:50 (Show Source): You can put this solution on YOUR website!let 3x="number of animals" x/2+x/3+x/8=69 __ multiplying by 24 (LCD) __ 12x+8x+3x=69*24 __ 23x=69*24 dividing by 23 __ x=72 __ substituting __ 3(72)=216