已知：X+Y=8,求：X²+16Y-Y²的值

解：X²+16Y-Y²

^=X2-Y2+16Y

^{=（X+Y)(X-Y)+16Y}

^=8(X-Y)+16Y

^=8X-8Y+16Y

^=8X+8Y

^=8(X+Y)

^=8*8

⁼⁶⁴