a. (X -1)(X + 2)

b. (X - 1)(X + 1)

c. (X + 2)(X + 1)

------------------------------------And they're to satisfy, 6X + 12 ??????

FOIL all.

a. = X^2 + X - 2

b. = X^2 - 1

c. = X^2 + 3X + 2

___________________I will be back.

Where is the ordered triple, X, Y, Z? All I could find here would be the value of X and there are not three variables here. Just looking at the expressions tell you the negative and positive X.

a. = (1 - 1)(- 2 + 2)

b. = (1 - 1)(- 1 + 1)

c. = (- 2 + 2)(- 1 + 1)

Usually with ordered triples you find the variable values one by one with manipulation of the expressions/equations and you keep inserting values into these expressions/equations to find the value of all three variables. I'm missing something here.