x⁶=(x²)³
y⁶=(y²)³
x⁶+y⁶=(x²)³+(y²)³=(x²+y²)·((x²)²-x²·y²+(y²)²)=(x²+y²)·(x⁴-x²·y²+y⁴)
x⁶+y⁶+x²+y²=(x²+y²)·(x⁴-x²·y²+y⁴)+(x²+y²)=(x²+y²)·(x⁴-x²·y²+y⁴+1)
x⁶=(x²)³
y⁶=(y²)³
x⁶+y⁶=(x²)³+(y²)³=(x²+y²)·((x²)²-x²·y²+(y²)²)=(x²+y²)·(x⁴-x²·y²+y⁴)
x⁶+y⁶+x²+y²=(x²+y²)·(x⁴-x²·y²+y⁴)+(x²+y²)=(x²+y²)·(x⁴-x²·y²+y⁴+1)