Find the greatest common factor of the terms in each of the following expressions:
3a2b2+4b2c2+12a2b2c2
HCF of 3, 4, 12 =1
HCF of a2,1,a2=1
HCF of b2,b2,b2=b2
HCF of 1,c2,c2=1
∴ HCF =b2
5a4+10a3−15a2
2xyz+3x2y+4y2