問題詳情

23. ( x 5)( -5x6+ x4) ( x 5)( -x6+ 6x4) (x )(6x6- 7x4) 與下列哪一個式子相同？
(A) (x+ 4)(6x6 -7x4)
(B) (x+ 6)(6x6- 7x4)
(C)- (x+ 6)(6x6 -7x4)
(D)- (x+ 4)(6x6- 7x4)

參考答案

答案：D
難度：計算中-1
書單：沒有書單，新增

用户評論

【Jiunndar Yeh】評論

(2x + 5)(-5x6 + x4) + (2x + 5)(-x6 + 6x4) + (x + 1)(6x6 - 7x4) = (2x + 5)[(-5x6 + x4) + (-x6 + 6x4)] + (x + 1)(6x6 - 7x4)= (2x + 5)(-6x6 + 7x4) + (x + 1)(6x6 - 7x4)= (2x + 5) * (-1)(6x6 - 7x4) + (x + 1)(6x6 - 7x4)= (6x6 - 7x4)[(-1)(2x + 5) + (x + 1)= (6x6 - 7x4)(-2x - 5 + x + 1)= (6x6 - 7x4)(-x - 4)= -(x + 4)(6x6 - 7x4)  ...選項(D)正確