\(2x-2y-x^2+y^2 \\=2(x-y)-(x-y)(x+y) \\=(x-y)(2-x-y)\)

\(2a^2+b^2+2c^2+2ab-2bc-2ca-4a-2c+5=0 \\<=>(a+b-c)^2+(a-2)^2+(c-1)^2=0 \\<=>a=2;c=1;b=-1 \\Suy\ ra\ S=(a-2)^{2022}+b^{2022}+c^{2022} \\=(2-2)^{2022}+(-1)^{2022}+1^{2022}=2\)

B

C

A

2. History

3. Physics

4. Maths

5. Geography

6. Biology

7. Science

B

?

?

?