How do solve the following linear system?: $2x - 3y = 1 , 3x + y = -20$ ?

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Answer 1 · 2016-07-13T08:51:30

$x = -59/11" and " y = -3 10/11$

The second equation contains a single $y$ term, so it is easy to transpose this to give: $y = -3x-20$

We now have an expression for $y$ in terms of x and can substitute that into the other equation:

$2x-3color(magenta)y =1 " and "color(magenta)(y = -3x -20$

$2x-3(color(magenta)(-3x -20)) =1$
$2x+9x+60 =1$

$11x= -59$

$color(blue)(x = -59/11)" "$ But $y = -3color(blue)x -20$
$y = -3(color(blue)((-59)/11)) -20$

$y = -3 10/11$

How do solve the following linear system?: 2x - 3y = 1 , 3x + y = -20 2x - 3y = 1 , 3x + y = -20 ?