Algebra

posted by .

I'm confused regarding the elimination method for
5x - 7y = -16,
2x + 8y = 26

  • Algebra -

    #1: 5x - 7y = -16
    #2: 2x + 8y = 26

    To eliminate y, multiply #1 by 8 and #2 by 7 to get

    40x - 56y = -128
    14x + 56y = 182

    If you add those two new equations, the y's are eliminated and you get

    54x = 54
    x=1

    Now you can go back and calculate y from one of the original equations.

  • Algebra -

    5 x - 7 y = - 16 Multiply both sides by - 2

    - 10 x + 14 y = 32


    2 x + 8 y = 26 Multiply both sides by 5

    10 x + 40 y = 130



    - 10 x + 14 y = 32

    10 x + 40 y = 130 Add equations


    - 10 x + 10 x + 14 y + 40 y = 32 + 130

    54 y = 162 Divide both sides by 54

    y = 162 / 54 = 3


    5 x - 7 y = - 16

    5 x - 7 * 3 = - 16

    5 x - 21 = - 16 Add 21 to both sides

    5 x - 21 + 21 = - 16 + 21

    5 x = 5 Divide both sides by 5

    x = 1


    Solutions :

    x = 1 , y = 3

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Algebra

    Systems of equations can be solved by graphing or by using substitution or elimination. What are the pros and cons of each method?
  2. Algebra

    Solving system of linear equations by using the apropiate method name the method and the x,y coordinates 1)X=4y+8 2x-8y=-3 2)3x-7y=6 elimination method 2x+7y=4 (2,0) 3)5x-2y=12 elimination method 3x-2y=-2 (7,23/2) 4)9x-8y=42 elimination …
  3. algebra

    Solve by elimination method. 2r-5s=-33 5r+2s=48 Solve by substitution method. 5x+6y=5 x-9y=40 I always get these two confused... can someone please help me with these two problems?
  4. algebra

    o Systems of equations can be solved by graphing or by using substitution or elimination. What are the pros and cons of each method?
  5. math elimination method

    elimination method really confuses me. solve by elimination method 5r -3s = 17 3r + 5s =17 A. solution is ______ (ordered pair, integer or fraction) B. Infinitely many C. No Solution
  6. Algebra

    Solve by elimination method. 7r-3s=14 3r+7s=64 Could never figure out the elimination method. Would love some help with this one. Thanks
  7. Algebra/Elimination method

    Solve using the elimination method. If the system has no solution or an infinite number of solutions, state this. -27x - 18y = -180 9x + 6y = 60
  8. math problem

    very confused could someone help me with this using the elimination method 5r-3s=16 3r+5s=30
  9. Algebra 1

    bobpursey, In this problem you helped me with earlier: Solve using any appropriate method. y = 2× - 5, y = ½× + 1 Substitution, substitute for y. 2×-5=½ × + 1 3/2 x=6 x=4 y= 2*4-5=3 How did you choose which method you were going …
  10. College Algebra

    Solve for elimination method,substitution method and cramer's rule for 8x - 4y + 2z =16

More Similar Questions