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Math Help - Need help with integers and equations...

  1. #1
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    Need help with integers and equations...

    I have to perform the following math problem:

    Select any two integers between -12 and +12 which will become solutions to a system of two equations. Then write TWO EQUATIONS that have your two integers as solutions and solve the system of equations using the addition/subtraction method.

    I am not quite sure how to even get started. Please help! Thanks
    Last edited by Kelmo7; July 17th 2008 at 05:02 PM. Reason: typos
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Kelmo7 View Post
    I have to perform the following math problem:

    Select any two integers between -12 and +12 which will become solutions to a system of two equations. Then write TWO EQUATIONS that have your two integers as solutions and solve the system of equations using the addition/subtraction method.

    I am not quite sure how to even get started. Please help! Thanks
    well, pick the two numbers, and make equations with them

    example, i pick 1 and 7, because i had 1 sandwich for breakfast this morning and your name is kelmo7. and just because, let x = 1 and y = 7


    ok, so 2(1) + 3(7) = 23

    so my first equation is 2x + 3y = 23

    another random arrangment:

    5(1) - 2(7) = -9

    so another equation is 5x - 2y = -9

    so my system is:

    2x + 3y = 23 ...................(1)
    5x - 2y = -9 ....................(2)


    come up with another system
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  3. #3
    A riddle wrapped in an enigma
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    Quote Originally Posted by Kelmo7 View Post
    I have to perform the following math problem:

    Select any two integers between -12 and +12 which will become solutions to a system of two equations. Then write TWO EQUATIONS that have your two integers as solutions and solve the system of equations using the addition/subtraction method.

    I am not quite sure how to even get started. Please help! Thanks
    Edit: Jhevon, this is the first post I've made today and you beat me to it!

    Let's say you pick (2, 3).

    Make up an expression with x and y, let's say 2x + 3y. How much is that? If you substitute the ordered pair (2, 3), the result is 13. Thus, your first equation is:

    2x +3y = 13

    Make up a second expression with x and y, let's say x + y. How much is that? Substituting, we have your second equation:

    x + y = 5

    The system is easy to solve using addition/subtraction method.
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  4. #4
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    Quote Originally Posted by Kelmo7 View Post
    I have to perform the following math problem:

    Select any two integers between -12 and +12 which will become solutions to a system of two equations. Then write TWO EQUATIONS that have your two integers as solutions and solve the system of equations using the addition/subtraction method.

    I am not quite sure how to even get started. Please help! Thanks

    Pick two integers. I will pick x1=2 and x2=-3.

    To come up with 2 equations, go ahead and write 2 expressions involving x1 and x2. Out of thin air, I will pick

    2 x1 + x2
    x1 - x2


    Now plug the values of x1 and x2 to see what those expressions equal.

    2 x1 + x2 = 1
    x1 - x2 = 5

    Now you have your 2 equations with 2 (known) unknowns. Try practicing with your own expressions. The only thing you have to be careful of is that the 2 expressions can't be the same up to a constant multiple.

    For example, don't pick x1 + x2 and 2 x1 + 2 x2. The second is just 2 times the first. This won't lead to two non-equivalent equations.

    Enjoy.
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  5. #5
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by masters View Post
    Edit: Jhevon, this is the first post I've made today and you beat me to it!
    hehe, sorry dude
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