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

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Answer 1 · 2016-05-25T06:10:28

$x=-2$
$y=1$

$3x+4y=-2" (1)"$
$-2x-3y=1" (2)"$

$"expand both sides of equation (1) by 2;"$
$6x+8y=-4$
$"rearranging the equation :" 6x=-4-8y" "(3)$

$"expand both sides of equation 2 by 3;"$
$-6x-9y=3$
$"rearranging the equation :"6x=-9y-3" "(4)$

$"Both ;the left sides of equations (3) and (4) are equal"$

$color(red)(6x)=-4-8y$
$color(red)(6x)=-9y-3$

$"The right sides of equations can be written as equal"$

$-4-8y=-9y-3$

$9y-8y=-3+4$

$y=1$

$"now use (1) or (2)"$

$3x+4*1=-2$
$3x+4=-2$
$3x=-6$
$x=-6/3$
$x=-2$

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