We
start with the following three equations:
1. y+1 =λ (6x-2y-2)
2. x = λ (-2x+6y+6)
3. (x+y+1)^2+2(y-x+1)^2 =
4
We
notice that if we add the first two equations we get the following:
x+y+1
= λ (6x-2y-2) + λ (-2x+6y+6) = λ(6x-2y-2-2x+6y+6)
= λ(4x+4y+4) = 4λ(x+y+1)
x+y+1
= 4λ(x+y+1) Therefore, λ = .25
Now
you have two equations and two unknowns.
·
y+1 =.25(6x-2y-2)
·
x = .25 (-2x+6y+6)
We
can simplify this to two equations that are basically the same (so we really
have one equation and two unknowns):
·
0= x-y-1
·
0= -x+y+1
We
can use the above to simplify equation #3, which reduces to (x+y+1)^2 = 4, or x+y+1 = 2, or x+y-1=0.
So
now we have two equations and two unknowns:
·
x-y-1=0
·
x+y-1=0
If
we add these two equations we get 2x – 2 = 0
Therefore,
x = 1.
If
x = 1, then y
= 0.