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

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Answer 1 · 2016-01-18T17:24:07

The solution for the system of equations is
$color(blue)(x=20/7 , y=-4/7$

$color(blue)(3x)+y=8$ ........equation $(1)$

$x-2y=4$ , multiplying by $3$
$color(blue)(3x)-6y=12$ .....equation $(2)$

Solving by elimination.

Subtracting equation $2$ from $1$ :
$cancelcolor(blue)(3x)+y=8$
$-cancelcolor(blue)(3x)+6y=-12$

$7y=-4$
$color(blue)(y=-4/7$

Finding $x$ from equation $2$

$x-2y=4$

$x=4+2y$

$x=4+2 xx (-4/7)$

$x=4+(-8/7)$

$x=28/7+(-8/7)$

$color(blue)(x=20/7$

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