Jawabanmu

2014-09-04T21:44:06+07:00
2014-09-04T21:49:32+07:00
(13a-8b)+(12a+9b) = 25a+b
(15i+14b+13k)+(-30i-45j+51k) = 15i+14b+13k-30i-45j+51k = 14b-15i-45j+64k