In
arithmetic and number theory, the least common multiple, lowest
common multiple, or smallest common multiple of two integers a and b, usually
denoted by LCM(a, b), is the smallest positive integer that is
divisible by both a and b. so the LCM of 3a^2b^4c^5 and 7a4bc^2
is a^2bc^2
so the exponent of b is 1
