111 111 化简得。= =t 6a b 6c 6a b 6c →a=,b=,C= 6t 6t 代入体积式 1= 6 6t t 6t → t=-, 6 ∴Ⅱ=1,b=6,cC=1, 所求平面方程为6x+y+6z=6. 上页, 6 1 1 6 1 a b c 化简得 = = 令 t a b c = = = 6 1 1 6 1 , 6 1 t  a = , 1 t b = , 6 1 t c = t t 6t 1 1 6 1 6 1 1 =    代入体积式 , 6 1  t = a = 1, b = 6, c = 1, 所求平面方程为 6x + y + 6z = 6