How do you solve the following system?: $3x+3y= -7 , 4x-y=-27$

Question

1428 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-02-16T17:09:30

The solution for the system of equations is:

$x= (-88)/15$

$y= 53/15$

$3x+color(blue)(3y)=-7$ ......equation $1$

$4x-y=-27$ , multiplying by $3$
$12x-color(blue)(3y)=-81$ .....equation $2$

Solving by elimination

Adding equations $1$ and $2$ :

$3x+cancelcolor(blue)(3y)=-7$

$12x-cancelcolor(blue)(3y)=-81$

$15x= -88$

$x= (-88)/15$

Finding $y$ from equation $1$ :
$3x+3y=-7$

$cancel3 xx (-88/cancel15)+3y=-7$

$(-88/5)+3y=-7$
$3y=-7 + 88/5$

$3y=-35/5 + 88/5$

$3y= 53/5$

$y= 53/15$

How do you solve the following system?: 3x+3y= -7 , 4x-y=-27 3x+3y= -7 , 4x-y=-27