Jawabanmu

2014-09-11T19:32:42+07:00
1. ( 13a - 8b ) + ( 12a + 9b ) 
     156 a kuadrat + 117 ab - 96 ab - 72 b kuadrat  
      156 a kuadrat + 21ab - 72 b kuadrat 

3.     3 - 17x + 35z + 4x + 23y - 9
        -13x + 23y + 35z - 6 
2014-09-11T20:34:45+07:00
1.(13a-8b)+(12a+9b)
= (13a+12a-8b+9b)
= 13a+12a-8b+9b
= 25a+b
2.(15i+14b+13k)+(-30i-45j+51k)
=(15i+(-30i)+14b+13k+51k+(-45j)
=15i-30i+14b+13k+51k+(-45j)
=-15i+14b+64k-45j
3.(3-17x+35z) dan (4x+23y-9)
=(3-17x+35z) + (4x+23y-9)
=(-17x+35z+4x+23y-9+3)
=-17x+35z+4x+23y-9+3)
=-17x+4x+35z+23y-9+3
=-13x+35z+23y-6
9.a. Kliling=a . 8
=8a
b. kliling=a+a+a+b+b+b+a+a+a+b+b+b
= 3a+3b+3a+3b
= 6a+6b
c.kliling=a+b+c+d+(b-d)+(a-c)
=a+b+c+d+b-d+a-c
=a+a+b+b+c-c+d-d
=2a-2b

maaf klo slah ya. itu jwbna sya sndri dan sudah di koreksi guru sya.
4,5,6,7,8 jg donk ... gk usah d kasih cara cuma mau ng cocokin doang