MaTh = Algebra = help

Solve this system of linear equaiton by an algebraic method.

So If I had to solve this the elimination method way, how would I do it?

x-2y = 10
3x-y = 0

  1. 👍
  2. 👎
  3. 👁
  1. x - 2y = 10
    3x - y = 0

    eliminate y by multiplying 3x - y = 0 by -2

    -2(3x - y = 0) = -6x + 2y = 0

    ADD the 2 equations
    x - 2y = 10
    -6x + 2y = 0
    -5x + 0 = 10
    -5x = 10
    x = -2

    substitute x = -2 in x - 2y = 10, to find y

    x - 2y = 10
    -2 - 2y = 10
    -2y = 12
    y = -6

    check x = -2, y = -6
    3x - y = 0
    3(-2) - -6 = 0
    -6 + 6 = 0
    0 = 0

    1. 👍
    2. 👎
  2. Oh so You have to multiply it by -2 because the first equation also uses -2 and you have to cancel them out that way right?

    So if its - and + that means you have to add the equations. If its - and - that means you have to subtract and if it's + and + that also means you have to subtract right?

    How did you get -2 as an answer?
    Did you divide 5x by 5 and 10 by five to get 2?

    You lost me right here:
    How did you do this?

    x - 2y = 10
    -2 - 2y = 10
    -2y = 12
    y = -6

    How did you get the second line?
    -2 - 2y = 10?

    And at the end you went 0 = 0
    so they have to equal to zero always?

    1. 👍
    2. 👎
  3. How did you get -2 as an answer?
    Did you divide 5x by 5 and 10 by five to get 2? YES

    You lost me right here:
    How did you do this?

    x - 2y = 10
    -2 - 2y = 10
    -2y = 12
    y = -6

    How did you get the second line?
    -2 - 2y = 10?

    to find the value of y, since you know x = -2, you plug x = -2 into either equation and solve for y

    the second line is from plugging -2 in for x in the equation x - 2y = 10

    x = -2
    x - 2y = 10
    -2 - 2y = 10
    -2y = 12
    y = -6

    yes, when you check, both sides will equal 0 if you are correct

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. finite math

    Solve the system of linear equations using the Gauss-Jordan elimination method. 3x−2y+ 4z = 22 2x+y− 2z = 3 x+ 4y − 8z = −16

  2. How do I do this.?(Math.)

    Use the Substitution method to solve the system of equations. y - 2x = -5 3y - x = 5 Solve one of the equations for x or y. Let's solve the first one for y: y - 2x = -5 y = 2x - 5 Now let's substitute 2x - 5 for y in the second

  3. algebra

    Use the substitution method to solve the linear system. Thanks! s= t+4 2t+s=19

  4. maths

    Solve the following system of linear equations using matrix method. i)2x+y-2z=10 y+10z=-28 3y+16z=-42

  1. maths

    1.solve the set of linear equation by matrix method.a+3b+2c=3,2a-b-3c=-8,5a+2b+c=9 solve for a,b,c 2.solve by Guassian elimination method, (a)a+2b+3c=5,3a-b+2c=8,4a-6b-4c=-2, (b)

  2. math

    If you try to solve a linear system by the substitution method and get the result 0 = 8, what does this mean? A. The system has one solution, (0,8). B.The system has one solution, (8,0). C.The system has no solutions. D.The system

  3. Algebra

    -3x + 2y = 8 x + 4y = -4 use substitution method to solve the linear system.

  4. Algebra/Precalculus

    Solve the system of linear equations and check any solutions algebraically. (If there is no solution, enter NO SOLUTION. If the system is dependent, express x, y, and z in terms of the parameter a.) 3x-3y+6z=6 x+2y-z=8 5x-8y+13z=4

  1. Math

    Solve by eliminnation methods 2x-4y=5 2x-4y=6 solve the system by elimination method 5x+2y= -13 7x-3y=17 Solve x+64 Determine whether the given numbers are solutions of the inequality 8,-10,-18,-3 y-8>2y-3 Solve by the

  2. algebra

    Solve the system of equations using the linear combination method. {9x+5y=35 2x+5y=0

  3. Calculus - Volume by Integration

    Find the volume of the solid generated by revolving the region bounded by the given lines and curves about the y-axis: y=(x-2)^3-2, x=0, y=25 (a)solve by either the disk or washer method (b)solve by the shell method (c)state which

  4. math

    What is the first step in solving the linear system {2x − 3y = 11 {−x + 5y = −9 by the substitution method in the most efficient way? A. Solve the first equation for x. B. Solve the first equation for y. C. Solve the second

You can view more similar questions or ask a new question.