How do you solve the system $x-y=11$ and $2x+y=19$ ?

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Answer 1 · 2015-06-30T04:03:21

The solutions are:
$color(blue)(x=10$

$color(blue)(y=-1$

$x-color(blue)(y) = 11$ ..........equation $(1)$
$2x +color(blue)(y )= 19$ ........equation $(2)$

Solving by elimination

Adding the two equations will eliminate $color(blue)(y$

$x-cancelcolor(blue)(y) = 11$
$2x +cancelcolor(blue)(y )= 19$

$3x = 30$
$color(blue)(x=10$

Now finding $y$ from equation $(1)$

$y = x-11$
$y =10-11$
$color(blue)(y=-1$

How do you solve the system x-y=11 x-y=11 and 2x+y=192x+y=19?