350xy - 70y = 70y * ( 5x - 1 )
4y + 10y = 2y * ( 2 + 5 ) = 14y
35xy - 7yz = 7y * ( 5x - z )
15a - 34a = a ( 15 - 34 ) = - 19a
44ab + 4bc - 3b = b ( 44a + 4c - 3 )
57n + 35n + n = n ( 57 + 35 + 1 ) = 93n
55xy - 15yz - y = y ( 55x - 15z - 1 )
17m - 3m + 5m - m = m ( 17 - 3 + 5 - 1 ) = 18m
