Odpowiedzi

2010-02-11T21:43:28+01:00
Opuszcasz nawiasy :) redukujesz tez wyrazy podobne
(5a+b-3)+(-3a-2b+7)= 5a+b-3-3a-2b+7=2a-b+5
2010-02-11T21:44:47+01:00
(5a+b-3)+(-3a-2b+7)= 5a+b-3-3a-2b+7 = 2a-b+4
(7x+y-1)-(-8x-y-1)= 7x+y-1+8x+y+1 = 15x+2y
3a(2a+4b)= 6a²+12ab
2x-6(2-x)= 2x-12+6x = 8x-12
6x+15= 6x+15
6x²y-9xy²-12xy²= 6x²y-21xy²
6x+15x²-8-20x= -14x+15x²-8
1 5 1
2010-02-11T21:46:04+01:00
= 5a+b-3-3a-3b+7=2a-2b+4
=7x+y-1+8x+y+1=15x+2y
=6a²+12ab
=2x-12+x
=6x+15
=6x²y-21xy²
=-14x+15x²-8
;))