<爆趕`明日交`11pm前要`40 marks> 各位知識朋友 , 入黎幫我手 ar !!! ( 數學F.2 ) (6)

(a)

(x + 2)(x + 2)

= x(x + 2) + 2(x + 2)

= x2 + 2x + 2x + 4

= x2 + 4x + 4

=====
(b)

(x + 2)[(x - 2) - 1]

= (x + 2)(x - 3)

= (x + 2)[(x + 2) - 5]

= (x + 2)(x + 2) - (x + 2)(5)

= (x2 + 4x + 4) - (5x + 10)

= x2 + 4x + 4 - 5x - 10

= x2 - x - 6

=====
(c)

(x + 2)(x + 48)

= (x + 2)[(x + 2) + 46]

= (x + 2)(x + 2) + (x + 2)(46)

= (x2 + 4x + 4) + (46x + 92)

= x2 + 4x + 4 + 46x + 92

= x2 + 50x + 96

=