Question

(x-3)(x+3) - (x-2) ² = ..?

Answer 1

x² -9 - (x²-4x+4) = x²-9 -x²+ 4x- 4= 4x-13

Answer 2

$(x-3)(x+3)-(x-2)^2=x^2-9-(x^2-2 \cdot x \cdot 2+2^2)= \\ =x^2-9-(x^2-4x+4)=x^2-9-x^2+4x-4=-13+4x$