Mathematics
ParticiaTufte63
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How to solv using elimination: 9x-2y=-21 2x+3y=16

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Jaywise

[latex]\begin{cases} 9x-2y=-21 /*3\\ 2x+3y=16 /*2 \end{cases}\\ \\\begin{cases} 27x-6y=-63\\ 4x+6y=32 \end{cases}\\--------- \\31x =-31/:31\\ \\x=-1[/latex] [latex]9*(-1)-2y=-21\\ \\-2y=-21+9\\ \\-2y=-12/:(-2)\\ \\y=6\\ \\\begin{cases} x=-1\\ y=6 \end{cases}[/latex]

Polieke

9x - 2y = -21  /·3 2x + 3y = 16  /·2 27x - 6y = -63 4x + 6y = 32 --------------------- 31x = -31  /:31 x = -1 2x + 3y = 16   ⇒   3y = 16 - 2x                            3y = 16 - 2 · (-1)                            3y = 18  /:3                              y = 6 Ans.: x = -1 y = 6

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