Հանրահաշիվ

263.(a+1)²-2×(a+1)+1=a²+2a+1-2a+2+1=a²+4=a²+2²

(m-n)²+2n×(m-n)+n²=m²-2mn+n²+2mn-2n²+n²=m²+2n²-2n²=m²

(p-q)²-2×(p²-q²)+(p+q)²=p²-2pq+q²-2p²+2q²+p²+2pq+q²=2p²+2q²+p²+3q²=4q²

(x+2y)²+2×(x²-4y²)+2y-x)²=x²+4xy+4y²+2x²-8y²+4y²-4xy+x²=4x²

266.

(1+x)×(1-x)×(1+x²)=(1-x²)×(1+x²)=1-x⁴

(m+n)×(n-m)×(m²+n²)=(n²-m²)×(m²+n²)=n⁴-m⁴

(a²-1)×(a²+1)=a²×a²+a²+a²-1=a⁴-1