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Recent problems solved by 'edjones'

edjones answered: 7568 problems
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Miscellaneous_Word_Problems/244841: Four students drive to school in the same car. The students claim they were late to school and missed a test because of a flat tire. On the makeup test, the instructor asks the students to identify the tire that went flat; front driver's side, front passenger's side, rear driver's side, or rear passenger's side. If the students didn't really have a flat tire and each randomly selects a tire, what is the probability that all four students select the same tire? 1 solutions Answer 179012 by edjones(7569)   on 2009-12-01 23:17:41 (Show Source): You can put this solution on YOUR website! 1/4^3=1/64 Not 1/4^4

Quadratic_Equations/244844: what kind of roots does x^2+2x+8=0 have? 1 solutions Answer 179009 by edjones(7569)   on 2009-12-01 23:15:07 (Show Source): You can put this solution on YOUR website! x^2+2x+8=0 the determinant, b^2-4ac = 4-32 = -28 Because the determinant is negative the roots are imaginary. . Ed

Square-cubic-other-roots/244789: square root of y+1 plus square root of y-4=5 1 solutions Answer 178966 by edjones(7569)   on 2009-12-01 21:28:04 (Show Source): You can put this solution on YOUR website! sqrt(y+1)+sqrt(y-4)=5 sqrt(y-4)=5-sqrt(y+1) y-4=y-10sqrt(y+1)+26 square each side -10sqrt(y+1)=-30 sqrt(y+1)=3 y+1=9 square each side y=8 . Ed

Quadratic_Equations/244790: how do you factor x^2=8x 1 solutions Answer 178963 by edjones(7569)   on 2009-12-01 21:14:58 (Show Source): You can put this solution on YOUR website! You solve it by factoring. x^2=8x x^2-8x=0 x(x-8)=0 x=0, x=8 . Ed

Graphs/244731: Please help me solve this equation: Solve by graphing x-y=2 x+y=6 Ihave tried graphing it but it comes out perpendicular i plotted (6,6) (-2,2) 1 solutions Answer 178957 by edjones(7569)   on 2009-12-01 21:01:19 (Show Source): You can put this solution on YOUR website! x-y=2 x+y=6 ------------add 2x=8 . x=4 y=2 . Ed . The graphing utility is not working properly tonight.

Inverses/244730: what is the step for 6n=27 1 solutions Answer 178955 by edjones(7569)   on 2009-12-01 20:58:06 (Show Source): You can put this solution on YOUR website! 6n=27 n=27/6 divide each side by 6 n=9/2 . Ed

Triangles/244725: Can you please help me solve the following problem: Can you tell me if you use the same method to solve this problem with similar problems using cos and sin? Thank you 1 solutions Answer 178952 by edjones(7569)   on 2009-12-01 20:54:38 (Show Source): You can put this solution on YOUR website! x=20/tan(73) x=6.115 . Ed

Triangles/244717: A triangle has sides 10ft, 25ft, and 26ft. Is it a triangle? 1 solutions Answer 178950 by edjones(7569)   on 2009-12-01 20:44:15 (Show Source): You can put this solution on YOUR website! yes

Quadratic_Equations/244688: for what values of b will the quadratic equation x^2+bx+10=0 have no real roots? 1 solutions Answer 178947 by edjones(7569)   on 2009-12-01 20:39:02 (Show Source): You can put this solution on YOUR website! x^2+bx+10=0 . b^2-4ac is the discriminant. It can't be less than zero and have real roots. a=1, c=10 b^2-40 discriminant b^2= 40 b=+-2sqrt(10) values of b with no real roots. . Ed

test/244681: two positive numbers are in the ratio of 5:12. if there product is 960 what is the positive diffrence between the two numbers 1 solutions Answer 178940 by edjones(7569)   on 2009-12-01 20:08:35 (Show Source): You can put this solution on YOUR website! Let x=a number that when multiplied by both 5 and 12 makes the resulting product 960. 5x*12x=960 60x^2=960 x^2=16 x=4 5*4=20 12*4=48 48*20=960 . 48 and 20 are the two numbers. . Ed

Graphs/244723: hello, i am trying to do my algebra and i am very lost. I need help graphing the solution set... X>0 Y>0 X+Y<6 1 solutions Answer 178934 by edjones(7569)   on 2009-12-01 19:43:46 (Show Source): You can put this solution on YOUR website! If both x and y are greater than zero then x+y must be greater than zero and the answer is an empty set. . Ed

Equations/244384: Please help, from Algebra II solve 3^3/5 thank you 1 solutions Answer 178774 by edjones(7569)   on 2009-12-01 00:27:05 (Show Source): You can put this solution on YOUR website! 3^3 / 5 = 27/5

Functions/244410: What is the domain of the given problem over 1 solutions Answer 178773 by edjones(7569)   on 2009-12-01 00:22:07 (Show Source): You can put this solution on YOUR website! x^2+3x =x(x+3) x can't be 0 or -3 because division by zero is not allowed. So the domain is all real numbers except 0 and -3. . Ed .

Proportions/244413: A train crosses a pole in 15 sec, while it crosses 100 meter long platform in 25 sec. the length of the train is: 1 solutions Answer 178770 by edjones(7569)   on 2009-12-01 00:12:38 (Show Source): You can put this solution on YOUR website! x/100 = 15/25 x/100 = 3/5 x=300/5 x=60 meters . Ed

Expressions-with-variables/244391: Ok, here is the next problem that I am facing. I can figure the first part, but cannot make sense of the second part. 5x+3y=-11 7x-2y=-17 2(5x+3y=-11) = 10x+6y=-33 3(7x-2y=17)= 21x-6y=51 10x+6y=-33 21x+6y=51 31x=18 x=18 31 Correct so far right? Here is what I can not figure out: I would then take X and substitute into either one of the equations. I chose the second one. 7(18/31)-2y=17 No logically, I would need to eliminate the y out of the equation somehow, but how? 7(18/31)-2y+2y=17, but then I would have to add it back on behind the 17 right? Here is what the example from Mathlab shows: So the only answer that I can derive from this is by multiplying 7(18/31) which equals 126/31, now what??? What do I do with the rest of the equation? 1 solutions Answer 178768 by edjones(7569)   on 2009-12-01 00:04:52 (Show Source): You can put this solution on YOUR website! 5x+3y=-11 7x-2y=-17 . 10x+6y=-22 not -33 21x-6y=-51 not 51 -----------------add 31x=-73 x=-73/31 . 5(-73/31)+3y=-11 replace x with -73/31 -365/31 +3y=-11 3y=24/31 y=8/31 . Ed

Square-cubic-other-roots/244064: Factor each polynomial x2 + 12x + 11 difference of two squares formula to factor. factor out any common factors. y(2) -49 4x(2)- 25 81x(2) - 1 The twos in () are exponets 1 solutions Answer 178657 by edjones(7569)   on 2009-11-30 15:09:37 (Show Source): You can put this solution on YOUR website! x2 + 12x + 11 (x+11)(x+1) . Ed

Graphs/244063: What is the solution to the system of equations that contains −3x + y = 3 and 2x − y = −1? 1 solutions Answer 178656 by edjones(7569)   on 2009-11-30 15:08:09 (Show Source): You can put this solution on YOUR website! -3x+y=3 2x-y=-1 --------------add -x===2 x=-2 y=-3 . Ed

Mixture_Word_Problems/243338: a can of cranberry juice contains 25 fluid ounces. How many quarts of cranberry juice are in a case of 24 cans? 1 solutions Answer 178320 by edjones(7569)   on 2009-11-28 23:05:27 (Show Source): You can put this solution on YOUR website! 25*24=600 600/32=18.75 quarts . Ed

Money_Word_Problems/243373: Please help me solve this problem. I cannot figure it out no matter how I hard I try. Interest of $322 is needed from 2 saving accounts. The total amount invested is $7600. Some is invested at 5% and the rest is invested at 4%. How much is invested at each rate? Thankyou if you can help. 1 solutions Answer 178317 by edjones(7569)   on 2009-11-28 22:54:54 (Show Source): You can put this solution on YOUR website! Let x=amt at 5% and 7600-x at 4% .05x+.04(7600-x)=322 .05x+304-.04x=322 .01x=18 x=$1800. 7600-1800=$5800. . Ed

Money_Word_Problems/243374: Please help me with this problem. A grocery store sells certain candies in bulk. The Good and Plenty cost $2.49 per pound and Sweet Treats cost $2.89 per pound. If Jane Strange takes 3 scoops of Good and Plenty and mixes it with 5 scoops of Sweet Treats, how much per pound should the mixture sell for? Assume each scoop contained the same weight of candy. Thankyou if you can help me as I am stuck on this. 1 solutions Answer 178314 by edjones(7569)   on 2009-11-28 22:47:11 (Show Source): You can put this solution on YOUR website! 3*2.49 + 5*2.89=21.92 21.92/8=$2.74/lb . Ed

Linear_Algebra/243372: The answer is I need help getting to the answer. the question is: simplify the answer: isn't correct. 1 solutions Answer 178311 by edjones(7569)   on 2009-11-28 22:39:21 (Show Source): You can put this solution on YOUR website! You have the correct answer for what you wrote. If you change 8p*8 to 8p-8 the answer will be 3p/2 . Ed

Miscellaneous_Word_Problems/243352: A manufacturer finds that the revenue generated by selling x units of a certain commodity is given by the function R(x)=264x-0.6x^2 where the revenue R(x) is measured in dollars. What is the maximum revenue, and how many units should be manufactured to obtain this maximum? 1 solutions Answer 178308 by edjones(7569)   on 2009-11-28 22:25:54 (Show Source): You can put this solution on YOUR website! R(x)=264x-0.6x^2 y=-0.6x^2+264x [y=ax^2+bx+c] a=-0.6, b=264, c=0 in this equation. . Maximum at x=-b/2a =-264/-1.2 =220 units to manufacture to obtain max revenue. . y=-0.6*220^2+264*220 =-29040+58080 =$29040. Max revenue. . Ed .

Quadratic_Equations/243356: I have to solve using the quadratic formula 2/x + 5/x+2 = 1 1 solutions Answer 178298 by edjones(7569)   on 2009-11-28 21:46:38 (Show Source): You can put this solution on YOUR website! 2/x + 5/(x+2) = 1 Use parentheses to help tutors. 2(x+2)+5x=x(x+2) multiply each side by x(x+2) (LCM) to eliminate fractions. 2x+4+5x=x^2+2x 7x+4=x^2+2x x^2-5x-4=0 . Ed . Solved by pluggable solver: SOLVE quadratic equation with variable Quadratic equation (in our case ) has the following solutons: For these solutions to exist, the discriminant should not be a negative number. First, we need to compute the discriminant : . Discriminant d=41 is greater than zero. That means that there are two solutions: . Quadratic expression can be factored: Again, the answer is: 5.70156211871642, -0.701562118716424. Here's your graph:

Travel_Word_Problems/243358: I am not sure how to handle this problem I hope you can help me Cassidy is standing 4 feet (west) in front of a tree. The tree is 10.5 feet high and she is 5 feet tall. Ift he sun casts a shadow from behind the tree (East) and Cassidy how long will its shadow be? 1 solutions Answer 178294 by edjones(7569)   on 2009-11-28 21:26:02 (Show Source): You can put this solution on YOUR website! How high is the sun in the sky?

Polynomials-and-rational-expressions/243364: Please help. Problem: x^3-8 Could you please provide a step process. I think that it will look something like this: (x^2+2)(x-4) 1 solutions Answer 178293 by edjones(7569)   on 2009-11-28 21:23:31 (Show Source): You can put this solution on YOUR website! x^3-8 (x-2)(x^2+2x+4) There are no steps. It is best to memorize this and x^3+8 which is (x+2)(x^2-2x+4) . Ed

Polynomials-and-rational-expressions/243283: x^2-25 over 5x+20 divided by x+4 over x-5 simplify? 1 solutions Answer 178292 by edjones(7569)   on 2009-11-28 21:17:36 (Show Source): You can put this solution on YOUR website! (x^2-25)/(5x+20) / (x+4)/(x-5) . Are you sure you copied the question right? . Ed

Expressions-with-variables/243107: how do I solve 5x + 6y-5(5x-9y+9z) 1 solutions Answer 178138 by edjones(7569)   on 2009-11-28 00:42:27 (Show Source): You can put this solution on YOUR website! This is not an equation. An equation has an equal sign with stuff on each side of it. This is an expression. 5x + 6y-5(5x-9y+9z) =5x+6y-25x+45y-45z =-20x+51y-45z . Ed

Equations/243115: Factorise; axy-ay+ax-a I think I've got the correct answer; (ay+a)(x-1) but I kind of just did trial and error. I was wondering if there's a faster or more straight forward way of getting there? Thanks SO much again (you guys are AWESOME!) manda 1 solutions Answer 178136 by edjones(7569)   on 2009-11-28 00:30:06 (Show Source): You can put this solution on YOUR website! You almost got it. axy-ay+ax-a =ay(x-1)+a(x-1) factoring by grouping. =(ay+a)(x-1) =a(y+1)(x-1) . Ed

logarithm/243112: Write as a single logarithm and simplify ( Do Not Fine Decimal Approximations) 2 log 6 + log x - log 12 1 solutions Answer 178135 by edjones(7569)   on 2009-11-28 00:16:54 (Show Source): You can put this solution on YOUR website! 2 log 6 + log x - log 12 log (6^2x/12) =log(3x) . Ed

Quadratic_Equations/243116: b) y = x2 – 4x + 5 Use the values of x provided in the table. x y 0 1 2 3 4 1 solutions Answer 178134 by edjones(7569)   on 2009-11-28 00:11:40 (Show Source): You can put this solution on YOUR website! y = x2 – 4x + 5 . x==> y 0==> 5 1==>2 2==>1 3==> 2 4==>5 . Ed .

Polynomials-and-rational-expressions/243030: What is 8/5x+4 minus 1/2x-3? 1 solutions Answer 178033 by edjones(7569)   on 2009-11-27 15:55:02 (Show Source): You can put this solution on YOUR website! 8/(5x-4) - 1/(2x-3) =(8(2x-3)-(5x-4))/((5x-4)(2x-3)) =(16x-24-5x+4)/(10x^2-23x+12) =(11x-20)/(10x^2-23x+12) . Ed