幫忙解數學

3x^2-36x+6 = 0
3(x^2-12x+2) = 0
A+B = 12
AB = 2

(A+B) - AB = 12 - 2 = 10

2006-10-23 22:49:17 補充：
A B = -bAB = c書上面係咁講, 不過佢唔係用AB, 而係用alpha & beta

如果無記錯的話,先用韋達定理求出兩根之和 and 兩根之積
A+B = - [(-36) / 3] = 12
A X B = 6 / 3 = 2
所以 ( A+B ) - (A X B) = 12 - 2 = 10

根和 = A + B = - ( -36 ) / 3 = 12
根積 = A * B = 6 / 3 = 2

所以, ( A + B ) - A * B = 12 - 2 = 10

唔係好明,可唔可能寫得清楚d...
thanks.

2006-10-23 22:49:31 補充：
(以上回答者及發問者)