. asdf: 2³ + 4³ + .. + (2n)³ = 2(2 + 4 + ... + 2n)² dla n + 1: 2³ + 4³ + ... + (2n)³ + (2n+2)³ = 2(2 + 4 + ... + 2n + 2n + 2)² 2(2+4 + ... + 2n)² + (2n+2)³ = 2(2 + 4 + .. + 2n + 2n + 2)² 2(2(1+2+..+n))² + (2n+2)³ = 8(1+2+...+n)² + (2(n+1))³ = 8(1+2+...+n)² + 8(n+1)³ =

	n(n+1)
8( (		)2 + (n+1)3) =
	2

	n2(n+1)2
8(		+ (n+1)3) =
	4

	n2(n+1)2 + 4(n+1)(n+1)2
8(		) =
	4

2( (n+1)² + (n² + 4n +4)) = 2((n+1)² + (n+2)²) = 2(2 + 4 + .. + 2n + 2n + 2)² = 2(2(1+2+...+n+n+1))² =

	n(n+1)
8((		+ n+1)2 =
	2

	n(n+1) + n+1
8((		)2 =
	2

2((n²+2n+2)) = 2(n+1)²

asdf:

	n2(n+1)2 + 4(n+1)(n+1)2
8(		) =
	4

2( (n²(n+1)² + 4(n+1)(n+1)²) = 2( (n+1)²(n² + 4n+4)) = 2(n+1)²(n+2)² a lewa strona to: 2(2+4+...+2n+2n+2)² =

	n(n+1)		2n +2
8(1+...+(n+1)2) = 8(		+		)2 =
	2		2

2(n(n+1) + 2n + 2)² = 2(n² + n +2n + 2)² = 2(n(n+1) + 2(n+1))² = 2((n+1)(n+2))² = 2(n+1)²(n+2)²