Answers

2016-02-17T19:59:40+08:00
X^2+3x-4

Use foil method
(x+4)(x-1)
x times x is x^2
x times -1 is -x
4 times x is 4x
4 times -1 is -4

x^2+-x+4x-4
x^2+3x-4 is the answer
0
(x+4)(x-1) 
use special product
There is no special product solution. The closest special product of binomials is Add times Subtract but it needs to be the same but the sign is different.
Byronn is right.  Further, as special product, this is "product of two binomials".  I'd explain it the same way assuming the inquirer does not understand how FOIL works :-)