Odpowiedzi

2010-02-28T15:45:56+01:00
2 x -2(1 - 2 + -1) -3(3 x -1 - 2 x 2 - 3) - 2 x 2(2 - -1 + 0,5) = -4 + 8 + 4 + 9 + 12 + 9 - 8 - 4 - 2 = 24
2010-02-28T15:49:51+01:00
B)
2a(1 - b + a ) -3(3a - 2b - 3) -2b(b - a + ½)=
2a-2ab+2a²-9a+6b+9-2b²+2ab-b =
-7a+5b+2a²-2b²+9 =
-7*(-1)+5*2+2*(-1)²-2*2²+9 =
7+10+2-8+9 =
20

2010-02-28T15:53:22+01:00
2a(1-b+a)-3(3a-2b-3)-2b(b-a+1/2)=
=2a-2ab+2a²-9a+6b+9-2b²+2ab-b=2a²-2b²-7a+5b+9
a=-1 b=2
2*(-1)²-2*(2)²-7*(-1)+5*2+9=2-8+7+10+9=20