Jawabanmu

2014-08-22T13:04:25+07:00
Pake rumus dasar (a+b)^2 = a^2 + 2ab + b^2 dan (a-b)^2 = a^2 - 2ab + b^2
2014-08-22T13:19:53+07:00
1. = (4a)^2 + 2*4a*9b +(9b)^2
=16a^2 + 72ab+81b^2
2. =(6a)^2 + 2*6a*(-5b) + (-5b)^2
=36a^2 - 60ab + 25b^2

semoga terbantu :)