Question

Determine:
N) 2x+4y=16
-3x+5y=9


O) 2x+3y=10
5x+6y=22

Answer 1

$n)\\\\ \left \{ {{2x+4y=16} \atop {-3x+5y=9}} \right. \\ \left \{ {{2x+4y=16\ .3} \atop {-3x+5y=9\ .2}} \right. \\ \left \{ {{6x+12y=48} \atop {-6x+10y=18}} \right. \\\\ Somando:\\\\ 22y = 66\\\\ y = \dfrac{66}{22}\\\\ y = 3\\\\ Substituindo:\\\\ 2x+4y=16\\ 2x + 4.3 = 16\\ 2x = 16 - 12\\ 2x = 4\\ x = 2$

$o)\\\\ \left \{ {{2x+3y=10} \atop {5x+6y=22}} \right. \\ \left \{ {{2x+3y=10\ .(-2)} \atop {5x+6y=22\ \ \ \ \ \ \ }} \right. \\ \left \{ {{-4x-6y=-20} \atop {5x+6y=22\ \ \ \ \ }} \right. \\\\ Somando: \\\\ x = 2\\\\ Substituindo:\\\\ 2x + 3y = 10\\ 2.2 + 3y = 10\\ 4 + 3y = 10\\ 3y = 10 - 4\\ 3y = 6\\ y = 2$

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