Factorization a ^ 2 + 6B ^ 2-5ab-2ac + 6BC Ask for detailed explanation

Factorization a ^ 2 + 6B ^ 2-5ab-2ac + 6BC Ask for detailed explanation

a^2+6b^2-5ab-2ac+6bc
1 -3
1 -2
-------
-5
Cross multiplication
=(a-3b)(a-2b)-2c(a-3b)
=(a-3b)(a-2b-2c)