Answer:
Step-1 : Multiply the coefficient of the first term by the constant 1 • -8 = -8
Step-2 : Find two factors of -8 whose sum equals the coefficient of the middle term, which is -18 .
-8 + 1 = -7
-4 + 2 = -2
-2 + 4 = 2
-1 + 8 = 7
Observation : No two such factors can be found !!
Conclusion : Trinomial can not be factored
Final result :
2 • (x2 - 18x - 8)