(a+b)²-9
=(a+b+3)(a+b-3)
1/4+(a-b)+(a-b)²
=[1/2+(a-b)]²
=(a-b+1/2)²
(a+b)²-9
=(a+b+3)(a+b-3)
1/4+(a-b)+(a-b)²
=(1/4)[4(a-b)²+4(a-b)+1]
=(1/4)(2a-2b+1)²
:(a+b)²-9
=(a+b+3)(a+b-3);
1/4+(a-b)+(a-b)²
=(a-b+1/2)²
(a+b)²-9=(a+b-3)(a+b+3)
1/4+(a-b)+(a-b)²=(1/2+a-b)²