How do you solve $-3x+y=-4$ and $2x+y=1$ using substitution?

Question

923 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-03-04T16:56:56

The solution for the system of equations is:
$color(green)(x=1$
$color(green)(y=-1$

$-3x+y=-4$ .......equation $(1)$

$2x +y=1$

$color(green)(y=1-2x$ ..................equation $(2)$

Substituting equation $(2)$ in $(1)$ :

$-3x+y=-4$

$-3x+color(green)(1-2x)=-4$

$-5x +1=-4$

$-5x =-4-1$

$-5x =-5$

$x =(-5)/(-5)$

$color(green)(x=1$

Finding $y$ from equation $2$ :
$y=1-2x$

$y=1-2 xx 1$

$y=1-2$

$color(green)(y=-1$

How do you solve -3x+y=-4-3x+y=-4 and 2x+y=12x+y=1 using substitution?