How do you solve -2x+y=8 and y=-3x-2?

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Answer 1 · 2015-09-08T13:33:26

The solution for the system of equation is
$x = - 2, y = 4$ $color(blue)(x=-2,y=4$

$- 2 x + y = 8$ $-2x+y=8$ ......equation $1$ $1$
$y = - 3 x - 2$ $y=color(blue)(-3x-2$ .....equation $2$ $2$

Solving by substitution.
Substituting equation $2$ $2$ in $1$ $1$

$- 2 x + y = 8$ $-2x+y=8$

$- 2 x - 3 x - 2 = 8$ $-2xcolor(blue)(-3x-2=8$

$- 5 x - 2 = 8$ $-5x-2=8$

$- 5 x = 8 + 2$ $-5x=8+2$

$- 5 x = 10$ $-5x=10$
$x = - 2$ $color(blue)(x=-2$

Finding $y$ $y$ by substituting $x$ $x$ in equation $2$ $2$

$y = - 3 x - 2$ $y=-3x-2$

$y = - 3 \cdot (- 2) - 2$ $y=-3*(-2)-2$

$y = 6 - 2$ $y=6-2$

$y = 4$ $color(blue)(y=4$