Jawabanmu

2014-09-07T09:56:14+07:00
1. a^2+14a+1a+14 = a(a+14)+1(a+14 ) = (a+1)(a+14)
2.a^2 -3a-7a+21 = a(a-3)-7(a-3) = (a-7)(a-3)
3. x^2+4x+4x+16 = x(x+4)+4(x+4) = (x+4)(x+4) = (x+4)^2