Post a New Question

math/algebra

posted by .

I have a question of how do I determine the variables when graphing linear equation? For an example graph x+2y=4, how do you come up with the variables as (0,2) (2,1) and (4,0)? The example in my book does not tell me how they came up with this. I know how to graph, I need to know how to come up with the variables.

  • math/algebra -

    basically, you pick any variable you want, and let the equation calculate the corresponding second variable.

    e.g. pick y=2, (one of their answer points)
    then x+2(2)=4
    x+4=4
    so x=0, then when x=0,y=2, which is the point (0,2)
    (the x is always written first, the y second)

    in general one would isolate one of the variables, in this case I would say
    x=4-2y
    Now by choosing any y value you want, you would generate a matching x value.
    e.g. let y =8, then
    x=4-2(8)
    x=-12 --------> point would be (-12,8) etc

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    Can someone correct this for me please or help me out.... Why are variables useful in algebra?
  2. Algebra-Graphing Linear Equation

    Y<2X+4 The way I unerstand from the book to graph this equation. I would start at the Y intersect and go up to 1. The go up 2 for the slope. Then across 4 on the X axis. The book shows the graph with the coordinates of (1,6) and …
  3. math

    what are the similarities and differences between an arithmetic sequence and a linear equation?
  4. Math

    Hi there I need help with the restrictions on the variables of this question: Simplify. State any restrictions on the variables. log(x^2+7x+12)/log(x^2-9) So my answer is: log(x+4/x-3) which is correct. Now for the restrictions, I …
  5. algebra 2

    how do u solve a system of linear equations in three variables?
  6. pre-algebra

    Explain the basic method(steps) for graphing a linear equation. Can you give an example of a linear equation and show me how to graph the equation?
  7. Linear Equations in Two Variables

    Find four solutions for each question and graph the equation. y=2x-3
  8. MATH ONE QUESTION!!!!!!

    The graph shows the number of handbags that Mandy made in one day. What are the variables?
  9. Math

    PLEASE CHACK MY ANSWER!!! Discussion for Applications of Linear Systems When solving a system of equations, how do you determine which method to use?
  10. Math (Stats)

    In order to predict y-values using the equation of a regression line, what must be true about the correlation coefficient of the variables?

More Similar Questions

Post a New Question