stumped

  1. J

    Stumped on math problem

    Hello, So, me and my brother were talking about math, and he asked me a question that I want some help on. Here is what he said: "Take any number x where x equals a non repeating decimal rational number. If x/y=a, and y equals a non repeating decimal rational number, then does there...
  2. A

    Help Proving Whether a Certain Rational Exists - Tried and I'm Stumped

    Trying to solve this: Let $r \in \, (0,1\, )$ and $r \notin \mathbb{Q}$. Let $r’ \in \, (0,1\, )$, $r’>r$, $r’ \notin \mathbb{Q}$, and $r’-r \notin \mathbb{Q}$. Let $q \in A = \{ r’-r+p : p \in \, (r,r+1\, ) \cap \mathbb{Q} \}$ Finally, one of the following statements must be true...
  3. H

    A 15 year old's math assignment has me stumped... any help?

    Hi All my kid wants my help here, but I am stumped too.:cold: The function(pl. see image) given has p & q as variables. - the graph has the horizontal asymptote line y = -3 -the graph intersects at (-1,5) find P and q. Thanks in advance !
  4. Crush

    I'm stumped! Mixing Liquid Concentrates

    This SHOULD be easy, but I don't know why I can't solve it. I've tried Excel and still can't do it. I've spent countless hours on this and am stumped! Suppose the concentrates below are all different chemicals. They also have the same consistency as water and can be used together to dilute each...
  5. Z

    Stumped. How to do this?

    Given an nxn-matrix A with entries aij = (10·i)^j-1 for i,j=1,....,n.Compute a vector b such that x =(1, 1,. .., 1) is the solution to the linear equation system Ax = b
  6. T

    A 10 year old's math assignment has me stumped... any help?

    The task: Using the digits of the year 1492 once and in the order that they appear in the year, and any of the following operations: square root, factorials, exponents, decimals, parentheses, negative numbers, addition, multiplication, subtraction, division, construct all numbers from 1 to 100...
  7. I

    Physics Grad Stumped By A 12 Year Old's Math Problem

    I am a little embarrassed that I have been unable to answer this question from my 12 year old son's Maths exam paper. I felt it was too tough for a 12 year old. Can anyone solve it? Erdos runs a Maths Club. Each time they meet, they each drink a pint of coffee with milk. The amounts of...
  8. J

    quadratic equation stumped

    Hey guys I am stumped on the penultimate and final line of the attached. Any help would be greatly appreciated in trying to figure out how they got to this. :spin: Thanks for the help J
  9. O

    Moving balls between bags - stumped!

    Bag A contains 3 red balls and 7 green balls. Bag B contains 7 red and 8 green balls. A ball is taken out of bag A and placed in bag B. Then a ball is taken out of B. a) Calculate that both the balls are red. P(A is red) = 3/10 then, since A has to come out we add the red to bag B and it...
  10. D

    Matrix Problem I am stumped on

    Find the transformation for the triangle with the given vertices: D(8,15) E(7,-4) F(4,-10) moved right 3 and down 1, then reflected about the x-axis, then rotated 172 degrees counter clockwise. I know the answer, but I don't have any idea how to get it. Answer is D1 = (-8.4, 15.4) E1 = (-10.6...
  11. N

    Factorising algebra!!! Stumped.

    Hi I've been given this question and told to factorise it and I have been shown the answer in stages, but I'm stuck on the first stage. Question: 1/2 (2n) (2n+1) - 1/2 (n-1) n Answer Stage 1 1/2 n (2(2n+1) - (n-1)) Stage 1, (blue section) where has the first single n come from? Is it because...
  12. H

    This equation has me stumped

    This is what I basically did: 25-x^2=(x+5)(x-5) which means multiply 6 by x-5 = 6x - 30. Multiply -9 by X+5 = -9x - 45. Combine them gets me -75-3x=8x. Add 3 gets 11x/-75. giving me a final answer of -75/11 What did i do wrong?!?!
  13. V

    Stumped on a function

    Here is the problem that has me stumped today. Find an equation of the line having the given slope and containing the given point. Express your answer in the form y=mx+b m=0, (0, -8 ) I came up with y=x+8 I used the formula y-y1=m(x-x1) the 1's are subscript sorry unsure how to input that.
  14. P

    Stumped simplifying this trig expression

    Need help simplifying! The answer key in my book swears I can simplify this further, but I don't see how! sin(arcsec(-5))cos(arcsec(-5)) There is an exact answer, but I can't arrive there unless I know the angle in radians... but this is not a common angle and I have no clue how to go about this.
  15. T

    Two Questions That Have Me Stumped

    Hey everyone, Could really use help on these two problems so I can finish studying for my math placement test tomorrow. 1) I need to find the set of real solutions if (3/3-x)=(1/3)-(1/x). Answer Choices are: A. empty set, B. {3}, C. {-3}, D. {3, -3}, E. {3i, -3i} 2) For which of the...
  16. E

    No good at maths! so stumped!

    Hi All, A posing question. Here's the scenario. Excel related! A Man sells cupcakes. Every cake costs 10P <FIGURE 1> (or what ever figure you want) and the profit is 20p if sold <FIGURE 2> (or whatever figure). Let's say that the man makes ten cupcakes(figure can change). So the total cost if...
  17. J

    Two Probability Questions, Stumped!

    So I have these two probability questions and probability is my weakest subject. These are suppose to be simple but I cannot wrap my mind around it. The first problem: "Suppose a family wants to have 3 children. Find the probability that the family has at least 1 boy." The second problem...
  18. C

    Tricky problem and I'm just stumped

    I'm in pre-calculus and every two weeks we have an assignment due. I have completed every step but the teacher always likes to throw us a curve ball on the final question. I have the class in 90 minutes and this is more of a last ditch effort at guidance but I'd still like to know anyways in...
  19. S

    Very Stumped on This Limit Problem

  20. M

    Stumped - Exponential Equation

    Here is the problem. Find all values of x such that x+3^{x}<4. I can see by inspection that the solution is x < 1. But I cannot see a way to solve this algebraically. Does anybody know what method I need to solve this?