Question 55643
I took a chance that you mis-typed your question and edited it, let me know if I was wrong.
{{{x^2-3x+4ax-12a}}} please factor  A big hint that you need to factor by grouping is having four terms.
{{{(x^2-3x)+(4ax-12a)}}}  Factor the GCF out of each group:
{{{x(x-3)+4a(x-3)}}}  They both have a common factor of (x-3) now.
{{{highlight((x+4a)(x-3))}}}
Happy Calculating!!!