Question 397336
For {{{ax^2 + bx + c}}} to be factorable using integers, it has to be factorable using rational numbers.  The condition is, the discriminant {{{b^2 - 4ac}}} has to be a perfect square rational number.  In your question, a = 8, b=-3, and c = -4.
==>  {{{(-3)^2 - 4*8*-4 = 137}}}
which is not a perfect square rational number.  Thus it cannot be factored using rational numbers, and hence not using integers.