(a²+b²)²—4a²b²
=(a²)²+(b²)²+2a²b²-4a²b²
=(a²)²+(b²)²-2a²b²
=(a²-b²)²
=[(a+b)(a-b)]²还有(m²—m)²+1/2(m²—m)+1/16(m²—m)²+1/2(m²—m)+1/16

=(m²—m)²+2×¼×(m²—m)+(¼)²
=[(m²—m)+¼]²
=[m²—m+¼]²
=[(m-½)²]²
=(m-½)^4（此处为四次方）