1. Let one side of the rectangle that is not against the wall be x meters, that is, the other side is (35-2x).

Then ① x (35-2x) =125x1= 5, x2 = 12.5.

② There is no solution for x (35-2x) = 250.

③x(35-2x)=300 without solution.

Therefore, it can reach125m2, with one side facing the wall 5m, the other side 25m or the other side12.5m and the other side10m. Not up to 250 or 300

2. ax 2+bx+c = 0 (a ≠ 0) is a general form of quadratic equation. If a=0 and there is no quadratic term, then the equation is guaranteed to be quadratic, and A cannot be equal to 0, so only (k 2-4k+5) ≠ 0 is explained.

Because k2-4k+5 = k2-4k+4+1= (k-2) 2+1.

(k-2) 2 ≥ 0 (square is nonnegative)

So (k-2) 2+ 1 ≥ 1 ≠ 0.

That is, no matter what value k takes, this equation is a quadratic equation with one variable.