I'm pretty sure it would be <span>x - y + 1 = 0 because if you plug in one of the coordinates into each equation, this is the only one that works.
</span><span>y - x + 1 = 0
2 - 1 + 1 = 0
2 = 0 not correct
</span><span>x - y + 1 = 0
1 - 2 + 1 = 0
0 = 0 correct
</span><span>-x - y + 1 = 0
-1 - 2 + 1 = 0
-2 = 0 not correct
</span>
QUESTION 1
We want to solve,

We factor the denominator of the fraction on the right hand side to get,

This implies


We multiply through by LCM of


We expand to get,

We group like terms and equate everything to zero,

We split the middle term,

We factor to get,





But

is not in the domain of the given equation.
It is an extraneous solution.

is the only solution.
QUESTION 2

We add x to both sides,

We square both sides,

We expand to get,

This implies,

We solve this quadratic equation by factorization,





But

is an extraneous solution
F(3)={2(3)-9}
F(3)={6-9}
F(3)={-3}
8/3 = 2 2/3 and -11/3 = -3 2/3
so the middle line is 0 and each big line is 1.
Put the first dot on 2 2/3 or right before the 3rd big line.
Put the second dot on -3 2/3 or the line right after the 4th big line going back from 0