Question #b5882

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Answer 1 · 2017-04-10T16:56:04

$x=-22/13$ and $y=-29/13$

Ill do the first one as an example,

$x-3y=5$ and $3x+7y=1$

The goal is to eliminate one of the variables so it is possible to solve for the other,

$x-3y=5$ equation 1
$3x+7y=1$ equation 2

Multiply the first equation by $3$ , and subtract the first equation from the second equation.

$3x-6y=30$
$3x+7y=1$

Subtracting the equations gives you,

$-13y=29$
$y=-29/13$

Now knowing $y=-29/13$ , you can solve for $x$ . Do so by subsituting the value for $y$ into equation 1.

$x-3(-29/13)=5$
$x+87/13=5$
$x=5-87/13$
$x=-22/13$

Therefore,

$x=-22/13$ and $y=-29/13$