How do you solve $x + y + 3$ and $2x + 3y = 9$ ?

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Answer 1 · 2015-09-05T07:39:35

The solution is
$color(blue)(x=-18, y=15$

Solving assuming that the first equation : $x+y+3=0$

$x+y=-3$ , multiplying this equation by 2:
$color(blue)(2x)+2y=-6$ ......equation $1$

$color(blue)(2x)+3y=9$ ............equation $2$

Solving by elimination.

Subtracting equation $2$ from $1$ eliminates $color(blue)(2x$

$cancelcolor(blue)(2x)+2y=-6$
$-cancelcolor(blue)(2x)-3y=-9$

$-y=-15$
$color(blue)(y=15$

Finding $x$ by substituting the value of $y$ in equation $1$
$x+y=-3$
$x=-3-y$
$x=-3-15$
$color(blue)(x=-18$

How do you solve x + y + 3x + y + 3 and 2x + 3y = 92x + 3y = 9?