From the first equation, x=-4-3y, so we can substitute for x in the second equation:
3y-4(-4-3y)=6, 3y+16+12y=6, 15y=-10, y=-โ
. So x=-4-3y=-4+2=-2.
Another way:
3y+x=-4
3y-4x=6
Subtract the second equation from the first:
5x=-10, x=-2. Therefore 3y+x=3y-2=-4, 3y=-2, y=-โ
.
SOLUTION: x=-2, y=-โ
.
Either way eliminates one variable and allows calculation of the other.