How do you solve the following linear system: $2x-5y=-4, -3x-8y=-1,$ ?

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Answer 1 · 2016-07-15T14:48:48

$x=-37$
$y=-14$

$2x-5y=-4" "(1)$
$color (red) (3) * (2x-5y)= color(red)(3) * (-4)$
$6x-15y=-12$

$color(green)(6x)=15y-12" "(3)$

$-3x-8y=-1" "(2)$
$color(red)(2) (-3x-8y)=color (red) (2) (-1)$
$-6x=-16y-2$

$color(green)(6x)=16y+2" "(4)$

$"we can write the equations (3) and (4) as equal"$

$15y-12=16y+2$
$-12-2=16y-15y$
$y=-14$

$"now let us use (1) or (2)"$
$2x-5(-14)=-4$
$2x+70=-4$
$2x=-70-4$
$2x=-74$
$x=-37$

How do you solve the following linear system: 2x-5y=-4, -3x-8y=-1, 2x-5y=-4, -3x-8y=-1, ?