What should be done to these equations in order to solve a system of equations by elimination? 3x+ y = 13 4x– 3y = 13

Question

What should be done to these equations in order to solve a system of equations by elimination?
3x+ y = 13
4x– 3y = 13

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Thu Thảo 6 months 2021-07-18T00:45:07+00:00 1 Answers 7 views 0

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    2021-07-18T00:46:29+00:00

    Answer

    You can multiply the first equation by 4 and the second equation by 3.

    You can multiply the first equation by 4/3.

    You can multiply the first equation by 3.

    Explanation

    When solving a system of equations by elimination, you want to add or subtract the equations to “get rid” of a variable.

    To do that, one of the variables in both equations have to have the same coefficient.

    The first answer possible gives x the coefficient of 12 for both equations. You would get 12x+4y=52 and 12x-9y=39. You could subtract those equations to get 13y=13.

    The second way gives x the coefficient of 4. You would multiply the first equation by 4/3 to get 4x+4/3y=52/3. You can subtract to get one variable, and then solve from there. Although, multiplying for 4/3 is annoying, so it’s not suggested.

    You can also “get rid” the the y. Multiply the first equation by 3 to get 9x+3y=39. You can add these equations. When you add 9x+3y=39 and 4x-3y=13 you get 13x=52.

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