(1) Quarter y ^ 2-xy + x ^ 2 (2) - A ^ 4 + 2A ^ 2b-b ^ 2 (3) In Polynomials: (1) x ^ 2 + XY + y ^ 2; (2) - x ^ 2 + 2xy-y ^ 2; (3) x ^ 2 + 2xy-y ^ 2; (1-x + quarter x ^ 2), it is () A.(1)(2)(3)B.(2)(3) C.(2)(4) D.(2)(3)(4) Question (1) (2) above is calculation

(1) Quarter y ^ 2-xy + x ^ 2 (2) - A ^ 4 + 2A ^ 2b-b ^ 2 (3) In Polynomials: (1) x ^ 2 + XY + y ^ 2; (2) - x ^ 2 + 2xy-y ^ 2; (3) x ^ 2 + 2xy-y ^ 2; (1-x + quarter x ^ 2), it is () A.(1)(2)(3)B.(2)(3) C.(2)(4) D.(2)(3)(4) Question (1) (2) above is calculation

Factorization? Question 1
The original formula = (1 / 2y-x) &
Question 2 - (A & # 178; - b) & # 178; - 7
All right, no square
1. (1/2y∧2-x)∧2
2. -(a∧2-b)∧2\7
Choose C