X+y+z=11, x-y+z=5, x-z=y+1 and solve it by any of the methods: isolation, elimination or determinants. isolation (or back substitution, would be for instance: z = 11-x-y, z=5-x+y, z = x-y-1 and then impose z=z:
11-x-y=5-x+y,
11-x-y=x-y-1,
The first takes you to: 6=2y or y=3, then the second to 12=2x or x=6, so that:
x=6, y=3, z=2.
You can see that it checks out
X=3/2, -5 is that what u are asking for
The y intercept is when x=0. That's solving the quadratic
0 = 2y² + 3y + 1 = (2y + 1)(y + 1)
y = -1 or 2y+1=0 so y=-1/2
Two y intercepts, (0,-1) and (0,-1/2)
Answer: -1 and -1/2
I believe the answer would be indirect proof as it would have no basis of evidence.
