x=y+z+2,x²=y²+z²+2yz+200 求 x+y+z=?

x=y+z+2,x²=y²+z²+2yz+200 求 x+y+z=?
x=y+z+2,x²=y²+z²+2yz+200 求 x+y+z=?

x=y+z+2,x²=y²+z²+2yz+200 求 x+y+z=?
由x=y+z+2,x²=y²+z²+2yz+200
得x-2=y+z,x²=(y+z)²+200
所以x²=(x-2)²+200
x²=x²-4x+4+200
4x=4+200
x=51
所以y+z=51-2=49
所以x+y+z=100