Answer: We are given the number 173.514
Each of the digits in this number has the following place value:

Secondly, We have to identify the numbers in digit 185.712
3 < 3x+6
-3<3x
-1<x
3x+6<24
3x<18
x<6
-1<x<6 the book is right
The factors of this expression would be (x+9)(x-2). You have to find two numbers that are factors of -18 that add up to 7. These numbers would be 9 and -2:
(9)x(-2)= -18
and 9 + (-2)= 7
Your answer is C) (x-2).