263
ա)(a+1)2-2(a+1)+1=a2+2a+1-2a-2+1=a2
բ)(m-n)2+2n(m-n)+n2=m2-2nm+n2+2nm-2n2+n2=m2+n2-2n2+n2=m2
գ)(p-q)2-2(p2-q2)+(p+q)2=p2-2pq+q2-2p2+2q2+p2+2pq+q2=p2+q2-2p2+2p2+p2+q2=2p2+2q2-2p2+2p2=4q2
դ)(x+2y)2+2(x2-4y2)+(p+q)2=x2+4xy+4y2+2+x2-4y2+p2+2pq+q2=2x2+4xy+2+p2+2pq+q2