Question

Factor completely: smiddle" class="latex-formula"> + 10x + 24
Prime
(x + 12)(x + 2)
(x + 3)(x + 8)
(x + 6)(x + 4)

Answer 1

24  = 6 * 4
and 
6 + 4 = 10


so its the last choice.

Answer 2

Oh yas I can do this.

   x² - 10x + 24
= (x___)(x___)    <--- Trial and error
= (x + 6)(x + 4)
= x² + 6x + 4x + 24   <--- Seeing if I am correct
= x² + 10x + 24

Therefore the answer is (x + 6)(x + 4)