FACTOR COMPLETELY
6abcx^2-42abcx-468abc
6abcx^2-42abcx-468abc
Start with numbers, namely 6
=6(abcx^2-7abcx-78abc)
the move on to each letter variable
=6a(bcx^2-7bcx-78bc)
=6ab(cx^2-7cx-78c)
=6abc(x^2-7x-78)
finally factor the quadratic expression
=6abc(x-13)(x+6)