Odpowiedzi

2009-12-02T19:11:43+01:00
A) (½a-4b)²=...1/4a²-4Ab+16b²
b) (x-y)(x+y)=...X²-Y²
c) (4+ √5z)(4-√5z)=16-√25z = 16+5z
d)(2a-6)²=4a²-24a+36
2009-12-02T19:21:57+01:00
(1/2a-4b)²=1/4a-2ab-2ab+16b=1/4a+16b

(x+y)(x-y)=x²-xy+xy-y²=x²-y²

(4+√5z)(4-√5z)=4²-√5z²=16+5z

(2a-6)²=(2a-6)(2a-6)=4a-12a-12a+36=4a+36

2009-12-02T19:26:32+01:00
A) (½a-4b)² = ¼a²-4ab+16b²

b) (x-y)(x+y) = x²-y²

c) (4+√5z)(4-√5z) = 16-√25z = 16-5z

d)(2a-6)² = 4a²-24a+36