Question

which trinomial is equivalent to (3x-1)(x+4)

Answer 1

Foil this out.
 first 3x*x outer
3x*4 Inner
-1*x last -1*4 multiply,
 combine like terms, and you'll have your answer

Answer 2

(3x - 1)(x +4)=
= 3x * x + 3x * 4 - 1 * x - 1 * 4 =
= 3x^2 + 12x - x - 4 =
= 3x^2 + 11x - 4