maths

Solve
5x + 3y = 4
3x + 4y = 9

Just a bit confused
Please help

  1. 👍 0
  2. 👎 0
  3. 👁 111
  1. first one times 3
    second one times 5

    15 x + 9 y = 12
    15 x + 20 y = 45
    ------------------subtract
    0 x - 11 y = - 33
    y= 3
    then go back for x
    5 x + 9 = 4
    5 x = -5
    x = -1

    1. 👍 0
    2. 👎 0
    posted by Damon
  2. 5x+3y=4 [eqn.1]
    3x+4y=9[eqn.2]
    now,
    x=4-3y/5[eqn.3]
    Now putting the value of x in eqn.2
    3(4-3y/5)+4y=9
    12-9y/5+4y=9
    12-9y+20y/5=9
    12+11y=45
    11y=33
    y=3
    And x=4-3y/5
    x=4-3*3/5
    x=4-9/5
    x=-1

    1. 👍 0
    2. 👎 0
    posted by riya

Respond to this Question

First Name

Your Response

Similar Questions

  1. help!

    A horizontal translation is applied to the graph of y= X^ 3 + 2 so that it will pass through (3, 10) what is the new equation for the graph? how do I do this? When x=3, one wants y to be 10 y= (x+a)^3 + 2 20= (3+a)^3 + 2 solve for

    asked by kris on August 28, 2006
  2. Math 8R - HELP!

    Simplifying Algebraic Expression Using the Distributive Property & Combining Like Terms Solve: 4 (g +7) = 64 4g + 4(4) = 64 4g + 16 = 64 I'm getting a bit confused and struggling a lot in this problem. Please help me!

    asked by Laruen on October 15, 2012
  3. Calculus help!

    On what intervals of t is the curve described by the given parametric equation concave up? Concave down? x=t^2; y=t^(3) + 3t I am a bit confused on how to solve this...any help/explanations are welcome!! (& greatly appreciated!)

    asked by Liz on April 16, 2013
  4. Calculus

    I'm a bit confused about the average equations with integration. I need to solve this problem, and I think I'm supposed to use substitution, but I can't get it to work. The problem looks like this: z(t)=4tsin(t^2), [0,π^1/2] Any

    asked by Rachel on February 27, 2011
  5. Data communication and Networking

    1. Illustrate the wave forms for data “101001000111010011110100” by using the following modulation techniques: a. 2 bit AM + 1 bit PM b. 2 bit FM + 1 bit AM c. 2 bit PM + 1 bit FM 2. Based on 8 bit ASCII code, illustrate a

    asked by Mohamed on January 18, 2019
  6. Business Communication

    Which way of asking for action carries the highest level of politeness? A. A polite order B. An indirect request C. A question D. An order I'm a bit confused as to what this question is asking for. However, I believe the answer

    asked by Rain Misoa on August 13, 2010
  7. Calc

    Find the integral from -∞ to -1 of 1/(1+x²) dx. I started working the problem out, and so far I got the lim as z→-∞ of [arctan (-1) - arctan (z)]. I'm a little bit confused exactly what is means when you plug -∞ into z,

    asked by Erica on October 24, 2011
  8. Math

    Solve: dA/dt = -10A, A(0) = 5 ------------------ I tried getting A by itself: A = -1/10 * dA/dt A(0) = 5 = -1/10 * dA/dt but I'm somewhat sure that's wrong; so integrating I get: int(dA/dt) = int(-10A) A = -5A^2 which doesn't make

    asked by James on August 7, 2018
  9. Biology

    I am a bit confused about conjugation, transduction and transformation. I understand the basics but how do they work? More confused with transduction and transformation. Thanks for any help in advance!

    asked by Anonymous on January 17, 2010
  10. Maths

    *I'm a bit confused with this qn* Expand and Simplify 3(3x-y)^2

    asked by Gilda on October 4, 2011

More Similar Questions