提示 记
等, 则
12(∑A - 2∑a)[20∑A(2a + b +c) + 37∑a² + 69∑bc]
= 2∑(b - c)²[126A + 10a - 59(b + c)]
+ 3∑(A - 2a)²[5(8a + 5b + 5c) - 36A]
+ 24∑(B - C)²[11(B + C) - 5(2a + 3b + 3c)]≥0.
等, 则12(∑A - 2∑a)[20∑A(2a + b +c) + 37∑a² + 69∑bc]
= 2∑(b - c)²[126A + 10a - 59(b + c)]
+ 3∑(A - 2a)²[5(8a + 5b + 5c) - 36A]
+ 24∑(B - C)²[11(B + C) - 5(2a + 3b + 3c)]≥0.
