Jawabanmu

2014-08-21T22:29:30+07:00
2014-08-21T22:31:32+07:00
A) - x^{2} +x+20
kali minus dulu jadi
 x^{2} -x -20 = (x-5)(x+4)
b)  -y^{2} -7y+30
kali (- )juga.
 y^{2} +7y-30 = (y-3)(y+10)