Solving a system of three equations with infinite many solutions

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  • Опубліковано 4 гру 2024

КОМЕНТАРІ • 27

  • @davidthaler7018
    @davidthaler7018 5 років тому +9

    You can almost tell how this will turn out just by looking.
    If you divide all terms in the first equation by 2, the result is a copy of the third equation. Using the two identical equations to eliminate a variable cancels ALL terms to zero, leaving you with a single equation in 3 variables, which has an infinite number of solutions.

  • @vandrickinman-benavente1975
    @vandrickinman-benavente1975 4 роки тому +8

    Well, you just saved my GPA by a full 2 points lol

  • @zxcvbnmaw1
    @zxcvbnmaw1 4 роки тому +10

    You don't actually show how to solve this...

  • @rampantfox1
    @rampantfox1 5 років тому +9

    Your second analysis of why there are infinitely many solutions is not quite correct. You used equations 2 and 3 to eliminate y, but - x - z = 7 alone does not imply infinitely many solutions. If this system had a solution, and you were going to solve it using elimination, you could eliminate y using equations 2 and 3, but you would also have to eliminate y using a different pair of equations. If you were unlucky enough to use equations 1 and 2, you would get a second equation in x and z alone. You would then take your first equation (which you call equation B) and this second equation and solve a 2x2 system. THAT process would yield a 0 = 0 case, and hence infinitely many solutions.

  • @santhoshmedishetty
    @santhoshmedishetty 5 років тому +1

    Please provide playlist of matrix

  • @alexz4006
    @alexz4006 5 років тому +18

    Thats not really solving the system though thats just saying that it has infinite solutions and its dependent

    • @Charlie-hv3dh
      @Charlie-hv3dh 3 роки тому +1

      Yeah, but in hs algebra 2 they really just want you to say “there’s infinitely many solutions” and that’s that.
      Scared of how you solve them though-

    • @RealShaquilleOneal
      @RealShaquilleOneal Рік тому

      @@Charlie-hv3dhbruh this is on the first test of the year and im only a sophomore so idk if i should drop the class or no

    • @nancy-zl8tl
      @nancy-zl8tl 7 місяців тому +1

      @@Charlie-hv3dh nah for us we actually have to solve for it [using one variable so for this i think it's (x, 5-x, -6)]

    • @Charlie-hv3dh
      @Charlie-hv3dh 7 місяців тому

      ahh alright @@nancy-zl8tl

    • @Charlie-hv3dh
      @Charlie-hv3dh 7 місяців тому

      omg a fellow swiftie@@nancy-zl8tl

  • @sanju.0000
    @sanju.0000 2 роки тому +1

    You could solve it easily with Cramer's Rule

  • @carlosjoaquinsantos1117
    @carlosjoaquinsantos1117 6 років тому +2

    I got Y=6; z=0; x= -7

    • @brianmclogan
      @brianmclogan  6 років тому

      do not see a mistake in my end

    • @michaelangeloelpedes8440
      @michaelangeloelpedes8440 4 роки тому

      y really is 6 , but z and x got infinite solution , x+z = -7 , z could be the -7 and x could be 0 , any number is possible as long x = -z - 7 and z = -x - 7

  • @carlosjoaquinsantos1117
    @carlosjoaquinsantos1117 6 років тому +3

    I dont know if i am right

    • @brianmclogan
      @brianmclogan  6 років тому

      I do not see a mistake on my end

  • @carlosjoaquinsantos1117
    @carlosjoaquinsantos1117 6 років тому +3

    I got the vlue of x y and z
    By multiplying the 1st equation by 3 and the 2nd Equation I multiplied it by -2

  • @hhenry2576
    @hhenry2576 5 років тому +1

    Not helping

  • @KW-gb9cd
    @KW-gb9cd 8 місяців тому

    Well, that was a waste of time.

    • @iamglued-so9mq
      @iamglued-so9mq 3 місяці тому

      @@KW-gb9cd Yes if you already knew this. Otherwise you would've been stumped when solving it for the first time