Find the greatest common factor of the terms in each of the following expressions:
2xyz+3x2y+4y2
HCF of 2, 3, 4 = 1
HCF of x,x2,1=1
HCF of y y,y,y2=y
HCF of z, 1, 1 = 1
∴ HCF = y
5a4+10a3−15a2
3a2b2+4b2c2+12a2b2c2