example.
2xz + 8xy + 5az + 20ay
You will group it.
(2xz+8xy) + (5az + 20ay)
You will think what number is visible in each term and what variable is common . then you will divide it .
2x (z + 4y) + 5a (z + 4y)
and make sure the two binomial is the same.
the answer will be .
(2x + 5a) (z + 4y)
