Question

resolva o sistema
{2x + 3y =19
{5x - 4y =13

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Answer 1

Resposta:

{2x + 3y =19. x=5 y=3

{5x - 4y =13 x= 5. y=3

Answer 2

Olá, siga a explicação:

$\displaystyle \left \{\sf {{2x + 3y = 19} \atop {5x-4y =13}} \right.$

Método de Substituição:

$\sf 2x + 3y = 19\\2x= 19-3y \\ \\x = \dfrac{19-3y}{2}$

$\sf 5x - 4y = 13 \\ \\5 \cdot \left ( \dfrac{19-3y}{2} \right ) - 4y = 13$

$\sf \dfrac{95 - 15y}{\dfrac {2}{1} } - \dfrac{3y}{ \dfrac{1}{2} } = \dfrac{13}{\dfrac{1}{2} } \\ \\ \\95 - 15y - 6y = 26 \\ \\ \\ -15y - 6y = 26-95 \\ \\ \\-9 y = -69 \\ \\ \\-21y= 69 \\ \\ \\\boxed {y \cong 3}$

$\sf x = \dfrac{19- 3(3) }{2} \\ \\x= \dfrac{19- 9}{2} \longrightarrow \boxed {x = 5}$

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