How do solve the following linear system?: -3x+7y=-1 , -x+3y=-5 ?

1 Answer
Dec 4, 2015

The solution for the system of equations is
color(blue)(x=-16,y=-7

Explanation:

-3x+7y=-1......equation 1

-x+3y=-5
color(blue)(x=3y+5..................equation 2

Solving by substitution :

Substituting equation 2 in equation 1:

-3x+7y=-1

-3 * (color(blue)(3y+5))+7y=-1

(-3) * (3y) + (-3) * (5)+7y=-1

-9y -15+7y=-1

-9y +7y=-1 +15

-2y=14

y=-14/2

color(blue)(y=-7

Finding x by substituting y in equation 2

color(blue)(x=3y+5

x=3 * (-7)+5

x=-21+5

color(blue)(x=-16

The solution for the system of equations is
color(blue)(x=-16,y=-7