10x²y³z³ – 6x²y²z – 4xy³z²

10, 6, and 4 can all be divided by 2, so we can take out a 2 factor

x², x², and x can all be divided evenly by x, so we can take out an x factor

y³, y², and y³ can all be divided evenly by y², so we can take out a y² factor 

z³, z, and z² can all be divided evenly by z, so we can take out a z factor

So we can take out 2xy²z. So we write this:

2xy²z(

To get the first term we divide 10x²y³z³ by 2xy²z and get 5xyz², so we
write that first in the parentheses:

2xy²z(5xyz²

To get the second term we divide –6x²y²z by 2xy²z and get -3x, so we
write that second in the parentheses:

2xy²z(5xyz² - 3x 

To get the second term we divide –4xy³z² by 2xy²z and get -2yz, so we
write that third in the parentheses and close the parentheses:

2xy²z(5xyz² - 3x - 2yz)

Edwin