xy+yz+xz+x*x+y*y+z*z 最简化的结果是什么?

条件是6x=4y=3z
2024-11-30 17:15:32
推荐回答(3个)
回答1:

xy + yz + xz + x*x + y*y + z*z

6x = 4y = 3z 变换为
x = 2a
y = 3a
z = 4a

原式 = (2*3 + 3*4 + 2*4 + 2*2 + 3*3 + 4*4)*a^2
= (6 + 12 + 8 + 4 + 9 + 16)*a^2
= 55*a^2
= 55/4*x^2

回答2:

xy + yz + xz + x*x + y*y + z*z
=1/2<(x+y).(x+y)+(y+z).(y+z)+(z+x).(z+x)>
再用那个关系式

回答3:

^^ ^ what's meaning?