Question

× - 5 y =8
-3 × + 4y = 25 ?
me ajudem é só essa pra Hoje?

Answer 1

$\left \{ {{x-5y=8} \atop {-3x +4y=25}} \right.$

$\left \{ {{x=8+5y} \atop {-3x+4y=25}} \right.$

- 3 · ( 8+ 5y ) + 4y = 25

- 24 - 15y + 4y = 25

- 24 - 11y =25

- 11y = 25 + 24

- 11y = 49

y=  $-\frac{49}{11}$

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x = 8 + 5 · ( $-\frac{49}{11}$ )

x = 8 - $\frac{245}{11}$

x = $-\frac{157}{11}$

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( x, y ) = ( $-\frac{157}{11}$ , $-\frac{49}{11}$ )

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( prova real)

$\left \{ {{\frac{-157}{11} -5 (\frac{-49}{11})=8   } \atop {-3} (\frac{-157}{11})+4 (\frac{-49}{11})=25  } \right.$

$\left \{ {{8=8} \atop {25=25}} \right.$

Espero ter ajudado!